Unit Test 1 Study Guide PDF

Unit Test 1 Topics Acids vs Bases Acids are substances with a pH less than 7, releasing hydrogen ions in water, while bases have a pH greater than 7, accepting hydrogens. Litmus paper turns red in acids and blue in bases, indicating their nature. Acids taste sour while bases taste bitter, fu...

Unit Test 1 Topics Acids vs Bases Acids are substances with a pH less than 7, releasing hydrogen ions in water, while bases have a pH greater than 7, accepting hydrogens. Litmus paper turns red in acids and blue in bases, indicating their nature. Acids taste sour while bases taste bitter, further distinguishing their characteristics. Acids react with metals to produce hydrogen gas, while bases can be corrosive if concentrated. The pH scale measures acidity or alkalinity, with lower values indicating more acidic and higher values showing more basic solutions. Catabolic vs Anabolic Reactions Catabolic reactions break down large molecules into smaller ones, releasing energy. Anabolic reactions build larger molecules from smaller ones, consuming energy. Catabolic reactions are exergonic, releasing energy, while anabolic reactions are endergonic, requiring energy. Catabolic reactions involve hydrolysis, while anabolic reactions involve dehydration synthesis. Examples of catabolic reactions include digestion, while examples of anabolic reactions include protein synthesis. Catabolic reactions are crucial for energy production, whereas anabolic reactions are essential for growth and repair. Cell Membrane Properties The cell membrane is a semipermeable lipid bilayer that regulates the passage of substances in and out of the cell. Composed of phospholipids, proteins, and cholesterol. Maintains cell shape and protects organelles. Facilitates cell communication and signaling. Helps maintain homeostasis by regulating the internal environment. Components of the cell theory The cell theory states that all living organisms are composed of cells, cells are the basic unit of life, and all cells come from pre-existing cells. Schwann and Schleiden proposed the cell theory in the 19th century. Virchow later added the idea of cell division to the cell theory. Advanced technology, like microscopes, helped in the development of the cell theory. The cell theory revolutionized the way scientists viewed life and paved the way for modern cell biology. Control vs Experimental Groups Control groups are exposed to the same conditions as the experimental groups, except for the independent variable being tested. The experimental group is subjected to the independent variable being tested. Control groups provide a baseline for comparison with the experimental group. Random assignment helps reduce bias in group selection. Blinding techniques ensure objectivity in data collection. Discovery of Penicillium The discovery of Penicillium by Alexander Fleming in 1928 marked a breakthrough in medicine due to its antibiotic properties. Penicillium is a type of mold that produces penicillin, a powerful antibiotic. Alexander Fleming noticed Penicillium's potential when he observed its ability to kill bacteria in a petri dish. Penicillin revolutionized the treatment of bacterial infections and saved countless lives. Fleming's discovery paved the way for the mass production of antibiotics and the development of new medical treatments. Enzyme components Enzyme components include the apoenzyme, which is the protein part, and the cofactor or coenzyme, which can be organic molecules or inorganic ions. Prosthetic groups are tightly bound cofactors that are essential for enzyme function. Metal ions like zinc, magnesium, and iron can serve as cofactors for enzymes. The holoenzyme refers to the active enzyme formed when the apoenzyme combines with its cofactor or coenzyme. Enzymes can be denatured if their components are disrupted, leading to loss of function. Gram-positive and Gram-negative differences Gram-positive bacteria have a thick peptidoglycan layer retaining the crystal violet stain, appearing purple under microscopy, while Gram-negative bacteria have a thinner layer and appear pink. Gram-positive bacteria are generally more susceptible to antibiotics targeting the cell wall due to their thicker peptidoglycan layer. Gram-negative bacteria have an outer membrane containing lipopolysaccharides that can trigger a stronger immune response. Gram-positive bacteria produce a simpler cell wall structure without an outer membrane. Gram-negative bacteria are more resistant to certain antibiotics and disinfectants due to their complex outer membrane. Importance of sample size Sample size is crucial for reliable results as it affects statistical power, precision, and generalizability in research. A larger sample size increases the likelihood of detecting true effects. Small sample sizes may lead to misleading or inconclusive results. Sample size determination should consider variability and effect size. Statistical analyses are more robust with larger sample sizes. Molecules of Life Molecules of Life are essential organic compounds found in living organisms that include carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates provide energy and structural support. Lipids are important for storing energy and forming cell membranes. Proteins play crucial roles in enzymes, structure, and signaling. Nucleic acids carry genetic information and are essential for protein synthesis. Organic vs Inorganic Organic compounds contain carbon and are typically derived from living organisms, while inorganic compounds lack carbon and are often minerals or salts. Organic molecules usually exhibit covalent bonding, whereas inorganic molecules can have various types of bonds. Examples of organic compounds include carbohydrates, lipids, proteins, and nucleic acids, while inorganic compounds include water, salts, and metals. Organic compounds are more complex and have a wider range of functions in living organisms compared to inorganic compounds. Study of organic vs. inorganic compounds is crucial in understanding the chemistry of life and the environment. parts of an experiment In an experiment, key parts include the hypothesis, variables, control group, experimental group, data collection methods, and conclusions. The hypothesis is a testable prediction. Variables are factors that can be changed. The control group serves as a baseline for comparison. The experimental group receives the treatment. Peer review process The peer review process involves experts in the field evaluating the quality and validity of research articles before publication. Helps maintain research quality and integrity in academic publications. Ensures that research articles meet specific standards for publication. Provides feedback to authors for improving their research. Usually involves anonymous reviewers to maintain objectivity. Prokaryotic vs eukaryotic cells Prokaryotic cells lack a true nucleus and membrane-bound organelles, while eukaryotic cells have a defined nucleus and organelles enclosed within membranes. Prokaryotic cells are typically smaller and simpler in structure compared to eukaryotic cells. Eukaryotic cells are found in plants, animals, fungi, and protists, whereas prokaryotic cells are found in bacteria and archaea. Eukaryotic cells undergo mitosis for cell division, while prokaryotic cells reproduce asexually through binary fission. Eukaryotic cells exhibit more complex metabolic processes and can be multicellular, while prokaryotic cells are mostly unicellular. Sources of Macronutrients Macronutrients are essential nutrients that our bodies require in large amounts for energy and growth. They include carbohydrates, proteins, and fats. Carbohydrates are found in foods like bread, pasta, and fruits. Proteins can be sourced from meat, dairy products, and legumes. Fats are commonly found in oils, nuts, and avocados. Balancing macronutrient intake is crucial for maintaining a healthy diet. Synthesized Amino Acids Synthesized amino acids are artificially created versions of naturally occurring amino acids, typically produced through chemical processes. Key methods for synthesizing amino acids include solid-phase peptide synthesis and liquid- phase peptide synthesis. Synthesized amino acids are used in research, drug development, and food production. These artificial amino acids can have modified structures that provide unique properties or functions. Synthesized amino acids must be carefully designed to mimic the properties of their natural counterparts. The Steps of Science The Steps of Science provide a systematic approach to conducting research, including making observations, forming hypotheses, conducting experiments, analyzing data, and drawing conclusions. Observations are key facts gathered through the senses. Hypotheses are testable explanations for observations. Experiments test the validity of hypotheses. Data analysis involves organizing and interpreting results. Water- or Fat-Soluble Vitamins Vitamins are classified as water-soluble or fat-soluble based on their solubility in water or fat. Water-soluble vitamins dissolve in water and are not stored in the body. Water-soluble vitamins include B-complex vitamins and vitamin C. Fat-soluble vitamins include vitamins A, D, E, and K. Excess water-soluble vitamins are usually excreted in the urine, while excess fat-soluble vitamins can be stored in the body. A balanced diet with a variety of foods is important to ensure adequate intake of both water- and fat-soluble vitamins. Key Terms Acid Acid is a chemical substance with a pH below 7 that releases hydrogen ions in water. Acids can be classified as strong or weak based on their ability to dissociate into ions in  water. Some common examples of acids include lemon juice, vinegar, and battery acid. Acids can react with metals to produce hydrogen gas. Acids can also be found in the stomach, where they aid in the digestion process. Activation energy Activation energy is the minimum amount of energy needed for a chemical reaction to occur. Activation energy is required because it helps overcome the energy barrier between the reactants and the transition state. Increasing the temperature increases the kinetic energy of the molecules, allowing them to overcome the activation energy more easily. Catalysts lower the activation energy by providing an alternative reaction pathway with a lower energy barrier. The activation energy can be influenced by factors such as concentration, surface area, and the presence of a catalyst. Active transport Active transport is a biological process that moves molecules across cell membranes against a concentration gradient, requiring energy, usually in the form of ATP. Active transport involves carrier proteins that facilitate movement of ions or molecules. Two types of active transport are primary (direct use of ATP) and secondary (uses electrochemical gradient). Examples include sodium-potassium pump, proton pump, and cotransport. It is key for maintaining cell potential and homeostasis in cells. Adhesion Adhesion is the property of different substances to adhere or stick together, usually due to intermolecular forces. Adhesion plays important roles in various biological processes, such as cell adhesion and the transport of water and nutrients in plants. Capillary action is an example of adhesion, where water molecules adhere to the walls of a narrow tube and are pulled upward against gravity. Adhesion is crucial for wound healing, as it helps cells stick together and form new tissues. Geckos are known for their ability to climb walls and ceilings due to their specialized toe pads that exhibit strong adhesion to surfaces. Anabolic Anabolic processes in living organisms involve building complex molecules from simpler ones, requiring energy input for growth, repair, and maintenance of cells and tissues. Protein synthesis is a key anabolic process responsible for creating proteins essential for cellular structure and function. Anabolic reactions are endergonic, meaning they require energy input to proceed. These processes are crucial for growth and development, as well as the repair of tissues and maintenance of body structures. Anabolic activities are often associated with activities such as muscle building and tissue repair in organisms. Anecdotal Evidence Anecdotal evidence refers to personal observations or experiences that are not based on systematic data collection or scientific research. It is subjective and can be influenced by bias or individual perspectives. Although anecdotal evidence can be compelling, it is generally considered weaker compared to empirical evidence. It is often used to generate hypotheses or as a starting point for further scientific investigation. Researchers must be cautious when relying on anecdotal evidence due to its limited reliability and potential for inaccuracies. Atom Atom is the basic unit of matter. It consists of a nucleus composed of protons and neutrons, surrounded by electrons in energy levels. Atoms are electrically neutral because they have equal numbers of protons and electrons. The nucleus is very dense, containing most of the atom's mass, while the electrons occupy much larger regions of space. Elements are defined by the number of protons present in their atoms. Electrons occupy distinct energy levels or orbitals around the nucleus, with each level capable of holding a specific number of electrons. Atomic mass Atomic mass refers to the average mass of the atoms in a sample of an element, taking into account the abundance of each isotope. The atomic mass unit (amu) is used to express atomic mass. Atomic mass is found on the periodic table as the decimal number below the element's symbol. Isotopes of an element have the same atomic number but different atomic masses. The atomic mass of an element is crucial for calculating molar mass and stoichiometric calculations. Atomic number Atomic number refers to the total number of protons in an atom's nucleus. Atomic number determines the element and its chemical properties. All atoms of the same element have the same atomic number. Atomic number is uniquely associated with each element on the periodic table. The atomic number can be found above or below the element's symbol in the periodic table. Base In biology, a base refers to a substance that can accept or react with hydrogen ions (protons). Bases have a pH value greater than 7 on the pH scale. Examples of bases include sodium hydroxide (NaOH) and ammonia (NH3). Bases are often used in the laboratory to neutralize acids. The chemical formula of a base usually contains hydroxide ions (OH-). Biology The scientific exploration involving the study of life and organisms, inclusive of their physical structure, chemical processes, molecular interactions, developments and evolutionary relationships. Lays the foundation for understanding the complex nature of life Emphasizes on cellular structure and functions, genetics and evolution Incorporates the study of ecosystems, behavior, and biodiversity Includes subfields such as microbiology, botany and zoology Bulk transport Bulk transport refers to the movement of large amounts of materials across the cell membrane. Materials are often transported in bulk to ensure efficient distribution throughout the organism. Examples of bulk transport include phagocytosis and pinocytosis. Bulk transport is an active process that requires energy in the form of ATP. In plants, bulk transport of water and nutrients occurs through structures like xylem vessels. Carbohydrates Carbohydrates are organic molecules made up of carbon, hydrogen, and oxygen atoms. They serve as a primary energy source and are found in foods like bread, rice, and fruits. Carbohydrates are classified as monosaccharides, disaccharides, or polysaccharides based on the number of sugar units they contain. Glucose, fructose, and galactose are examples of monosaccharides. Lactose, sucrose, and maltose are examples of disaccharides. Starch, glycogen, and cellulose are examples of polysaccharides. Catabolic Catabolic processes involve the breakdown of complex molecules into simpler substances, releasing energy in the process. Catabolism includes processes like digestion, cellular respiration, and fermentation. Enzymes play a crucial role in catalyzing catabolic reactions. ATP is often produced during catabolic reactions, providing energy for cellular activities. Catabolic pathways help organisms obtain energy by breaking down nutrients. Cell membrane The cell membrane is a semi-permeable barrier encircling cells, regulating molecular traffic to maintain a stable internal environment and supporting cellular structure. It's composed of a lipid bilayer interspersed with proteins. It's involved in processes like endocytosis, exocytosis, and signal transduction. Proteins embedded in the membrane fulfill functions like transport and receptor signaling. Membrane fluidity is influenced by lipid composition and temperature. Cell theory The cell theory is a fundamental concept in biology that states all living organisms are composed of cells, cells are the basic unit of structure and function in living organisms, and all cells arise from pre-existing cells. Cells are the smallest unit of life and are capable of carrying out essential functions. The discovery of cells and the development of cell theory is credited to scientists Robert Hooke, Anton van Leeuwenhoek, and Matthias Schleiden and Theodor Schwann. The cell theory was proposed in the mid-19th century and revolutionized the understanding of life and biology as a whole. The cell theory serves as the foundation for many branches of biology, including genetics, microbiology, and cell biology. Cell wall The cell wall is a rigid outer layer found in plants, fungi, and some prokaryotes, providing support and protection for the cell. The cell wall is made up of cellulose in plants, chitin in fungi, and peptidoglycan in prokaryotes. It is not present in animal cells. Cell walls allow plants to stand upright and resist mechanical stress. The cell wall also helps in preventing the entry of pathogens and provides shape to the cell. Chloroplast Chloroplasts are double membrane-bound organelles found in plants and algae that contain chlorophyll, responsible for photosynthesis. Chloroplasts are the site of photosynthesis, where sunlight energy is converted into chemical energy. The two main stages of photosynthesis, light-dependent and light-independent reactions, occur in separate regions of the chloroplast. Chloroplasts contain their own DNA and ribosomes, allowing them to synthesize their own proteins. Chlorophyll, which gives plants their green color, is located in the thylakoid membranes within the chloroplast. Coenzymes Coenzymes are organic molecules that are required for the proper functioning of enzymes. They participate in enzyme-catalyzed reactions and can transfer chemical groups between molecules. Coenzymes act as cofactors, which means they bind to the enzyme and help it carry out its function. They can be derived from vitamins or other organic molecules and are often modified during the reaction. Coenzymes are often involved in energy transfer processes, such as ATP synthesis. Some coenzymes function as carriers of electrons or other chemical groups in metabolic pathways. Cofactors Cofactors are molecules required for the proper functioning of enzymes, helping them catalyze certain reactions effectively. Cofactors can be either inorganic ions (like zinc or magnesium) or organic molecules (like vitamins). Some cofactors are permanently bound to the enzyme, while others can bind and detach as needed. Cofactors assist enzymes by providing additional chemical groups or helping with electron  transfer reactions. Enzymes are often inactive without their cofactors and may require cofactor binding to become fully functional. Cohesion Cohesion is the property of water molecules to stick together due to hydrogen bonding, forming a continuous chain that allows water to flow and be pulled upward in plants. The cohesion between water molecules creates surface tension, allowing small insects to walk on water. Cohesion is responsible for the transport of water and nutrients within plants through the xylem. Cohesion helps to maintain the shape and structure of water droplets. Cohesion is important for the movement of water from the roots to the leaves in plants through capillary action. Covalent bond A covalent bond is a type of chemical bond where two atoms share electrons, resulting in the formation of a molecular structure. Covalent bonds are formed between nonmetallic elements. The electrons are shared in such a way that the atoms involved achieve a stable electron configuration. Covalent bonds can be polar or nonpolar, depending on the electronegativity difference between the atoms. These bonds are stronger than ionic bonds and weaker than metallic bonds. Cytoplasm Cytoplasm is the jelly-like fluid that fills the cell, excluding the nucleus. It contains various organelles and is responsible for supporting cell structure and housing cellular processes. Cytoplasm is composed of water, salts, proteins, and other molecules. It allows for the movement of organelles within the cell. Many cellular reactions, including protein synthesis, occur in the cytoplasm. Cytoplasm helps maintain cellular shape and acts as a cushion to protect the organelles. Cytoskeleton The cytoskeleton is a network of protein fibers that provides shape, structure, and support to cells.  The cytoskeleton is composed of three main types of fibers: microtubules, microfilaments, and intermediate filaments. Microtubules are hollow tubes made of the protein tubulin, and they help maintain cell shape and assist in cell division. Microfilaments are made of the protein actin and are involved in cell movement, contraction, and support. Intermediate filaments provide mechanical support and help anchor organelles within the cell. Electrons Electrons are negatively charged particles that orbit the nucleus of an atom. Electrons play a crucial role in chemical bonding and the formation of molecules. Electrons can exist in different energy levels or shells around the nucleus. Electrons are involved in the process of oxidation-reduction reactions in living organisms. Electrons are involved in the transfer of energy through electron transport chains in cellular respiration. Endosymbiotic theory The 'Endosymbiotic Theory' posits that mitochondria and chloroplasts in eukaryotic cells used to be individual prokaryotic organisms that later developed a symbiotic relationship with eukaryotes. It was proposed by biologist Lynn Margulis. The theory explains the origin of eukaryotes from prokaryotes. It supports evolution by suggesting that collaboration can drive complexity. The theory is supported by genetic and functional similarities between mitochondria, chloroplasts, and bacteria. Energy "Energy" refers to the ability to do work or cause changes, playing a vital role in all life processes from movement to growth. "Energy" is mostly derived from food in living organisms. Metabolism involves converging "Energy" into a usable form, ATP. "Energy" in ecosystems flows from producers to consumers. "Energy" conservation is a fundamental concept in life processes, aligning with the 1st law of thermodynamics. Enzymes Enzymes are proteins that act as catalysts in living organisms, expediting chemical reactions without being consumed by these processes. Enzymes work by lowering the activation energy of a reaction. Each enzyme catalyses a specific reaction, often associated with its name. Enzymes can be influenced by factors such as temperature and pH. Enzyme activity can be inhibited, either completely (non-competitive) or temporarily (competitive). Epidemiology Epidemiology is the study of the distribution and determinants of health-related states or events in specific populations, and the application of this study to control health problems. It involves analyzing patterns, causes, and effects of health and disease in populations. Epidemiologists use various methods to identify risk factors and improve public health outcomes. Key aspects include disease surveillance, outbreak investigation, and statistical analysis of data. Epidemiology plays a crucial role in shaping public health policies and interventions. Eukaryotic Eukaryotic organisms are characterized by the presence of a nucleus and other membrane- bound organelles. Eukaryotic cells include plants, animals, fungi, and protists. The DNA in eukaryotic cells is organized into linear chromosomes within the nucleus. Eukaryotic cells are generally larger in size than prokaryotic cells. Eukaryotic organisms are able to carry out complex functions due to the specialized organelles within their cells. Experimental control group The experimental control group is a standard group used as a baseline for comparison in an experiment to determine the effect of the independent variable. Ensures any changes observed are due to the independent variable. Helps in establishing cause-and-effect relationships. Receives all factors present in the experimental group except for the independent variable. Provides a basis for comparison to assess the impact of the independent variable. Experimental test group The experimental test group is a group in an experiment that is exposed to the experimental treatment or condition being studied. Typically compared to a control group that does not receive the treatment. Results from the test group are compared to evaluate the effects of the treatment. Important to have a large enough sample size in the test group for reliable conclusions. Random assignment helps ensure that factors other than the treatment do not influence the results. Facilitative diffusion Facilitative diffusion is the passive movement of molecules across a cell membrane with the help of specific carrier proteins. Carrier proteins aid in transporting molecules down their concentration gradient. It allows for the movement of larger or charged molecules that cannot diffuse through the lipid bilayer. Facilitative diffusion does not require energy input from the cell. It is crucial for the uptake of important nutrients and ions by cells. Golgi apparatus The Golgi apparatus is an organelle found in eukaryotic cells that processes and packages proteins and lipids. The Golgi apparatus consists of flattened membranous sacs called cisternae. It receives proteins from the endoplasmic reticulum and modifies them through processes such as glycosylation. It then packages and sorts the modified proteins into vesicles. The Golgi apparatus plays a crucial role in the secretion of proteins and the transport of lipids within the cell. Gram + bacteria Gram + bacteria have a thick layer of peptidoglycan in their cell walls that retains the crystal violet stain in Gram staining. These bacteria appear purple under a microscope after the staining process. They are usually sensitive to antibiotics like penicillin that target the cell wall. Common examples include Staphylococcus and Streptococcus species. Gram + bacteria tend to have simpler structures compared to Gram - bacteria. Gram - bacteria Gram-negative bacteria have cell walls with a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides, making them appear pink under a Gram stain. They are more resistant to antibiotics due to the presence of the outer membrane. Common examples include E. coli, Pseudomonas aeruginosa, and Salmonella. Gram-negative bacteria are associated with various infections in humans such as pneumonia, urinary tract infections, and meningitis. They are classified based on their shape, metabolism, and other characteristics. Homeostasis Homeostasis is the self-regulating process by which biological systems maintain stability while adjusting to changing external conditions. Involved in maintaining body temperature, fluid balance, and blood pH levels. Disruptions can lead to diseases such as diabetes and hyperthyroidism. Regulated largely by the endocrine and nervous systems. Feedback mechanisms, both negative and positive, play a key role in homeostasis. Hypertonic In biological terms, 'Hypertonic' refers to a solution with a higher solute concentration compared to another solution. It can cause cells to shrink in a process called crenation Aquatic organisms may face challenges due to hypertonic solutions In humans, hypertonic saline can help treat certain lung diseases It plays a key role in osmosis, the movement of water across a cell's membrane Hypotonic A hypotonic environment refers to a solution with lower solute concentration, allowing the net movement of water molecules into the cell via osmosis. In a hypotonic solution, a cell will swell as water moves inside. This is due to higher solute concentration inside the cell. Plant cells thrive in hypotonic solutions due to their rigid cell walls. In animal cells, a hypotonic environment may cause cell burst or lysis. Inorganic molecule Inorganic molecules are compounds that do not contain carbon-hydrogen bonds; examples include water, salts, and metals.  Inorganic molecules play essential roles in biological systems, such as in maintaining pH balance and transporting ions. Water, a crucial inorganic molecule, is involved in various metabolic reactions and serves as a universal solvent in living organisms. Inorganic salts provide necessary nutrients for cellular functions and are involved in nerve signal transmission. Some inorganic molecules, like metals, act as cofactors in enzymes, influencing their catalytic activity. Ionic bond An 'Ionic bond' is a type of chemical bond formed through the electrostatic attraction between oppositely charged ions, typically between a metal and a non-metal. Ionic bonds create compound structures termed as 'ionic compounds'. They play a key role in the structure and function of proteins. These bonds influence cell signaling and interactions. They determine properties of substances, including solubility in water. Isotonic In biological terms, 'isotonic' refers to a state where a cell and its surrounding solution have equal solute concentrations, resulting in no net movement of water. Isotonic solutions are ideal for human cells to maintain normal functionality. Isotonic environments prevent cell damage due to excessive shrinking or swelling. In isotonic conditions, diffusion or osmosis does not occur. Isotonic solutions are commonly used in intravenous fluids to treat dehydration or other medical conditions. Lipids Lipids are a diverse group of organic compounds, insoluble in water but soluble in nonpolar organic solvents, primarily composed of carbon, hydrogen, and oxygen. Lipids function as energy storage molecules, thermal insulation or as part of cellular membrane structures. Examples include fats, oils, waxes, phospholipids, and steroids. They are vital for energy storage and regulate body functions like inflammation and immunity. Dietary lipids can also provide essential fatty acids that the body cannot synthesize. Lysosome Lysosomes are small membrane-bound organelles containing digestive enzymes that break down waste materials and cellular debris.  Lysosomes are involved in the process of autophagy, where the cell degrades and recycles its own components. The acidic pH inside lysosomes is important for the proper functioning of their enzymes. Lysosomal storage disorders occur when lysosomes lack specific enzymes needed for the digestion of certain molecules. Lysosomes can fuse with endocytic vesicles, allowing them to digest material brought into the cell through the process of endocytosis. Macronutrients Macronutrients are essential nutrients required in large quantities by living organisms for growth, development, and energy production. There are three main macronutrients: carbohydrates, proteins, and fats. Carbohydrates are the body's preferred source of energy and can be found in foods like grains, fruits, and vegetables. Proteins are important for building and repairing tissues, and can be found in foods like meat, fish, and dairy products. Fats are a concentrated source of energy and can be found in foods like oils, butter, and nuts. Malnutrition Malnutrition refers to a condition characterized by an insufficient or imbalanced diet that can lead to health problems. Malnutrition can result in stunted growth, weakened immune system, and increased susceptibility to diseases. Both overnutrition (excessive intake of nutrients) and undernutrition (insufficient intake of nutrients) are forms of malnutrition. Lack of access to nutritious food, poverty, and certain medical conditions can contribute to malnutrition. Malnutrition can affect people of all ages, but children, pregnant women, and the elderly are particularly vulnerable. Metabolism Metabolism refers to all chemical processes occurring in a living organism to maintain life, including converting food to energy and building or replacing cellular components. It's categorized into catabolism (breaking down) and anabolism (building up). Enzymes speed up metabolic reactions by lowering activation energy. Some factors affecting metabolism are age, sex, weight, and genes. Metabolic rates vary across individuals and species. Micronutrients Micronutrients are essential nutrients required by the body in small amounts for optimal health and proper functioning of various biological processes. Micronutrients include vitamins and minerals, such as iron, zinc, vitamin C, and vitamin D. These nutrients play important roles in maintaining metabolic functions, preventing nutrient deficiencies, and supporting growth and development. Not consuming enough micronutrients can lead to various health problems, including weakened immune system and impaired cognitive function. Obtaining micronutrients from a balanced diet that includes a variety of fruits, vegetables, whole grains, and lean proteins is essential for overall well-being. Minerals Minerals are essential nutrients that the human body needs in small amounts to maintain proper functioning. Minerals cannot be made by the body and must be obtained through the diet. Minerals play important roles in bone health, nerve function, muscle contraction, and maintaining fluid balance. Examples of minerals include calcium, iron, potassium, magnesium, and zinc. Deficiencies or excesses of certain minerals can lead to health problems and imbalances in the body. Mitochondria Mitochondria are organelles found within eukaryotic cells that function as the cell's power producers, generating most of the ATP energy cells require. The number of mitochondria within a cell varies depending on the cell's energy needs. Mitochondria have their own DNA, separate from the cell's nuclear DNA. Through a process called cellular respiration, mitochondria convert nutrients into energy. Disorders in mitochondria can lead to various diseases, like Alzheimer's and Parkinson's. Molecule A 'Molecule' is the smallest unit of a chemical compound that retains the chemical characteristics of that compound. Constructed of two or more atoms bonded together. Can form from the same or different types of atoms. Governs the processes of life, such as cellular respiration. May be simple as in water, or complex as in DNA. Neutrons Neutrons are subatomic particles found in the nucleus of an atom. They have no charge and help stabilize the atom. Neutrons have a mass similar to protons, but they have no charge. The number of neutrons in an atom can vary, resulting in different isotopes of the same element. Neutrons play a crucial role in nuclear reactions and are often used in scientific research and medical applications. The stability of an atom is influenced by the ratio of neutrons to protons in its nucleus. Nucleic acids Nucleic acids are macromolecules that store and transmit genetic information in cells, consisting primarily of DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). They are made up of nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base. DNA is double-stranded and forms a duplex, while RNA is typically single-stranded. Nucleic acids are responsible for protein synthesis in cells through the process of transcription and translation. Mutations in nucleic acids can lead to genetic disorders and diseases. Nucleus of a cell The nucleus is a membrane-bound organelle that houses the cell's genetic material, directing cellular activities and regulating gene expression. Contains DNA in the form of chromosomes. Surrounded by a nuclear envelope that controls what enters and exits. Contains the nucleolus, responsible for ribosome synthesis. Plays a crucial role in cell division and replication. Nucleus of an Atom The nucleus of an atom is the central core that contains protons and neutrons, with electrons orbiting around it in various energy levels. The number of protons in the nucleus determines the element's identity. Neutrons help stabilize the nucleus. Electrons are located outside the nucleus in electron shells. Nucleus is tiny compared to the overall size of the atom. organic molecule An 'organic molecule' refers to any chemical compound containing carbon atoms, usually in long chains or rings, and often combined with atoms of other elements, notably hydrogen. Characteristically found in and produced by living organisms. Examples include proteins, carbohydrates, lipids, and nucleic acids. Many also contain oxygen, nitrogen, sulfur, phosphorous. Vital in processes like respiration, digestion, and reproduction. Osmosis Osmosis is a process facilitating the diffusion of water across a selectively permeable membrane from a low solute concentration to a high solute concentration. Osmosis equalizes solute concentrations on either side of a membrane. This movement continues until equilibrium is reached. Osmosis is vital for fluid balance in cells. It plays a crucial role in nutrient and waste transport in organisms. Passive transport Passive transport is a cellular process for moving molecules and other substances across membranes without the use of cellular energy. It involves diffusion and osmosis. It's governed by the substance's concentration gradient. It moves substances from high to low concentration. Fat-soluble molecules and gases often utilize this method. Peer-reviewed journals Peer-reviewed journals are publications where articles are reviewed by experts in the field before being accepted for publication, ensuring high quality and reliability. Authors submit articles for consideration, and editors select reviewers to evaluate the work. Reviewers provide feedback on the article's quality, methodology, and validity of findings. The peer-review process helps maintain the credibility of scholarly research. Published articles often include citations to other reputable sources, enhancing the paper's credibility. Peer review Peer review is a process in which experts in a particular field evaluate scientific research before it is published in a journal. The purpose of peer review is to ensure the quality and reliability of scientific research. Peer review involves multiple rounds of evaluation and feedback. The reviewers are usually anonymous to maintain objectivity. The peer review process can be time-consuming and may take several weeks or even months. Penicillium Penicillium is a genus of mold known for producing the antibiotic penicillin, which revolutionized medicine by treating bacterial infections. Penicillium species are found in diverse environments, such as soil, air, and decaying organic matter. Penicillium spores are spread through the air and can cause allergic reactions in some individuals. Some species of Penicillium are also used in the production of various types of cheeses. The discovery of penicillin by Alexander Fleming from Penicillium mold marked a major breakthrough in the field of medicine. Phospholipids Phospholipids are a class of lipids that are a major component of all cell membranes. They can form lipid bilayers because of their amphiphilic characteristic. They consist of a glycerol molecule, two fatty acids, and a phosphate group. The amphiphilic nature arises from the hydrophilic 'head' and hydrophobic 'tails'. Phospholipids provide a barrier in cellular membranes to protect the cell. They also play a role in signal transmission and lipid transport. pH scale The pH scale is a logarithmic scale used to determine the acidity or alkalinity of a solution. It ranges from 0 (very acidic) to 14 (very alkaline), with 7 being neutral. Substances below pH 7 are acidic, while substances above pH 7 are alkaline. Each unit represents a tenfold difference in acidity or alkalinity. pH 6 is ten times more acidic than pH 7. The pH of blood in the human body should be around 7.4 for proper functioning. pH indicators, like litmus paper, change colors to represent different pH values. Polarity of Water Water's polarity is due to its uneven distribution of electrons, causing one side to be slightly negative and the other side slightly positive. This polarity allows water to form hydrogen bonds, creating cohesion and adhesion properties. Due to its polarity, water is an excellent solvent, dissolving polar substances and forming solutions. The high polarity of water results in high surface tension, allowing objects to float on its surface. Water's polarity is essential for various biological processes, such as transporting nutrients and maintaining cell structure. Process of Science The 'Process of Science' involves making observations, forming a hypothesis, conducting experiments, analyzing data, and drawing conclusions to advance knowledge. It is an iterative process involving testing and refining ideas. Peer review helps ensure the credibility of scientific findings. Variables are carefully controlled to isolate cause and effect relationships. Scientific theories are based on well-supported evidence. Prokaryotic Prokaryotic organisms are unicellular organisms that lack a nucleus and membrane-bound organelles. Prokaryotes include bacteria and archaea, and are generally smaller and simpler than eukaryotic cells. Prokaryotes have a single circular chromosome located in the nucleoid region. Prokaryotic cells reproduce asexually through binary fission. Prokaryotes are found in diverse habitats, including soil, water, and extreme environments like hot springs and deep-sea hydrothermal vents. Properties of Life Properties of Life refer to the characteristics that define living organisms, including organization, energy utilization, growth, adaptation, and reproduction. Living organisms are organized structures with complex systems of cells and tissues. They acquire and utilize energy for various life processes. Growth involves the increase in size or number of cells or organisms.  Adaptation refers to the ability of organisms to adjust to their environment for survival. Proteins Proteins are large, complex molecules essential for all living organisms, performing crucial functions such as catalyzing metabolic reactions and DNA replication. Composed of one or more chains of amino acids. Their structure and function are determined by the sequence of these amino acids. They play a vital role in cellular processes, including cell structure and transport. Deficiency or malfunction can lead to diseases like Alzheimer's. Protons Protons are positively charged particles found in the nucleus of an atom. Protons have a mass of approximately 1 atomic mass unit. The number of protons determines the element of the atom. Protons are responsible for forming chemical bonds with electrons. Protons can be gained or lost in chemical reactions, resulting in the formation of ions. Randomized clinical trial A randomized clinical trial is a research study that randomly assigns participants to different groups to compare the effects of different treatments. Participants are assigned to treatment groups randomly to minimize bias and ensure validity. These trials are considered the gold standard for testing the effectiveness of medical treatments. Randomization helps ensure that any observed differences between groups are due to the treatment and not other factors. Double-blind randomized trials involve participants and researchers being unaware of the treatment assignment to further reduce bias. Ribosome A ribosome is a cell organelle that serves as the site of protein synthesis. It translates messenger RNA into polypeptides, a process known as translation. Ribosomes are composed of ribosomal RNA and proteins. They exist in both eukaryotes and prokaryotes, functioning similarly. In eukaryotes, ribosomes can be found free-floating in the cytoplasm or attached to the endoplasmic reticulum. In antibiotics research, prokaryotic ribosomes are often targeted to inhibit protein synthesis,  affecting the organism's growth. Rough endoplasmic reticulum Rough endoplasmic reticulum is a network of membrane-bound tubules with ribosomes attached, involved in the synthesis and transport of proteins. It is located near the nucleus in eukaryotic cells. The ribosomes on the rough ER are responsible for producing proteins. The rough ER helps in the folding and modification of newly synthesized proteins. It plays a crucial role in the transportation of proteins to different parts of the cell. Sample size Sample size refers to the number of individual observations or data points collected for a study or experiment to ensure statistical reliability. Increasing sample size generally leads to more reliable and accurate results. A larger sample size can help in detecting smaller effects or differences. A small sample size may not be representative of the entire population. Sample size calculation is important to determine the number of participants needed for a study. Science Science is a systematic and logical study involving observation, experimentation, and analysis to understand the natural world. Scientific method is used to formulate hypotheses, conduct experiments, and draw conclusions. Scientists rely on empirical evidence, quantitative data, and peer-reviewed research to support their findings. Science is an ongoing process that is constantly evolving and refining our understanding of the world. Knowledge gained through science can be applied to solve real-world problems and improve our quality of life. Scientific method The 'Scientific method' is a systematic procedure for conducting research, involving observation, hypothesis formulation, experimentation, and interpretation of data. Hypotheses are educated guesses made based on observations. Experiments are conducted to test these hypotheses.  Data from experiments are analyzed and interpreted. Conclusions are drawn, leading to new hypotheses or theories. Scientific Theory Scientific theory is a well-subvened explanation of natural phenomena supported by empirical evidence, experimentation, and scientific reasoning. Theories are not mere guesses but explanations based on extensive research. Theories can evolve over time with new evidence and understanding. Theories must be testable and able to make predictions. Theories are fundamental in shaping scientific knowledge and understanding. Simple diffusion Simple diffusion is the spontaneous movement of molecules or ions from an area of higher concentration to an area of lower concentration. It does not require energy input from the cell. It occurs down a concentration gradient. It is responsible for the movement of gases, such as oxygen and carbon dioxide, across cell membranes. It plays a crucial role in maintaining the balance of ions and nutrients in cells. Smooth endoplasmic reticulum Smooth endoplasmic reticulum is a network of tubular membranes within a cell that lacks ribosomes on its surface, involved in lipid synthesis, detoxification of drugs, and storage of calcium ions. Smooth ER is involved in the detoxification of various drugs and metabolic byproducts. Smooth ER plays a role in lipid metabolism, including the synthesis of steroid hormones. It is responsible for the storage and release of calcium ions, which are important for muscle contraction and cell signaling. Smooth ER is abundant in cells that are involved in lipid secretion, such as liver cells and cells in the adrenal glands. Solute A 'Solute' is a substance that is dissolved in a solution, usually in smaller amount compared to the solvent. The solute, when dissolved, may change the physical properties of the solvent, like boiling and freezing points.  Solute concentration influences osmosis, playing a vital role in cellular function. Examples of solutes include salts, sugars, and gases like oxygen and carbon dioxide. Solutes can be separated from their solutions through processes like evaporation and distillation. Solution In scientific terms, a 'Solution' refers to a homogeneous mixture consisting of two or more substances, typically a solute dissolved in a solvent. The substance in higher quantity is called the solvent. The substance in lesser quantity is called the solute. An example is salt water, where water is the solvent and salt is the solute. Solutions are important in many cellular processes such as diffusion and osmosis. Solvent A 'Solvent' is a substance, typically liquid, that dissolves solutes (often solids), creating a solution. 'Solvent' aids in the transportation of molecules, allowing for chemical reactions. Water is a universal 'Solvent' due to its polar nature. The interaction between solutes and 'Solvent' can affect solubility. The type of 'Solvent' used can greatly influence a reaction's rate. Vitamins Vitamins are essential organic compounds needed in small quantities for the proper functioning and development of the body. Vitamins are classified into two types: water-soluble (such as vitamin C and B-complex) and fat-soluble (such as vitamins A, D, E, and K). Widely available in various foods, vitamins play a crucial role in maintaining a healthy immune system, promoting growth and development, and preventing chronic diseases. A deficiency in certain vitamins can lead to specific health problems, such as vitamin C deficiency causing scurvy or vitamin D deficiency leading to weakened bones. Excessive intake of some vitamins can also have adverse effects on health, so it's important to consume them in recommended amounts.