Life Science PDF

Life Science ➔ Macromolecules ◆ What is an Atom? Basic building blocks for all matter in the universe Extremely small and are made up of a few even smaller particles ○ Electrons-negative charge ○ Protons-positive charge ○ Neutrons-neutral charge Atoms fit together with other atoms to make up matter ◆ How do atoms make up elements? There are different kinds of atoms based on the number of electrons, protons, and neutrons each atom contains Each different kind of atom makes up an element There are 92 natural elements, and up to 118 when you count in man-made elements ◆ Inorganic VS Organic There are 6 essential elements for living things ○ Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur Elements combine to make molecules Molecules are either inorganic or organic ○ Inorganic molecules do not contain the element carbon ○ Organic molecules contain the element carbon ◆ Monomers & Polymers Monomers are small molecules which may be joined together in a repeating fashion to make more complex molecules Polymers are complex molecules that are made of repeating monomers ◆ Organic Compounds - The Core 4 Carbohydrates ○ Elements: Carbon, Hydrogen, Oxygen ○ Monomer: Monosaccharide (Glucose) ○ Polymer: Polysaccharide ○ Function: Main source of energy (short term energy) ○ Examples: Glucose, Fructose (Simple Sugars) Cellulose, Starch (Complex Sugars) Lipids ○ Elements: Carbon, Hydrogen, Oxygen ○ Monomer: Fatty Acid ○ Polymer: Triglyceride ○ Function: Long term energy, waterproof covering, makes up the cell membrane ○ Examples: Oils, Waxes Proteins ○ Elements: Carbon, Hydrogen, Oxygen, Nitrogen ○ Monomer: Amino Acids ○ Polymer: Polypeptide (Protein) ○ Function: Animal structures, fights diseases, transports materials, controls reaction rates ○ Examples: Hormones and Enzymes Nucleic Acids ○ Elements: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus ○ Monomer: Nucleotide ○ Polymer: Deoxyribonucleic acid and Ribonucleic acid ◆ Enzymes: A special type of protein Enzymes are catalysts, or substances that speed up chemical reactions ○ Lower the energy needed to start the reaction Can build up or break down other molecules ○ The molecules they act on are called substrates These reactions are the processes that keep all plants and animals functioning Enzymes help the body perform such tasks as digestion and growing new cells Can be destroyed by high temperatures & high pH ➔ Cell Organelles ◆ Cell Theory All living things are composed of one or more cells The cell is the basic unit of life in all living things New cells are produced from existing cells ◆ Cell Organelles What is a cell? ○ Tiny units of life that are like specialized factories, full of machinery designed to accomplish the business of life. ○ Cells make up every living thing, from the blue whales to the small bacteria that we cannot see. ○ Cells make up the organs and tissues in your body. ○ They do important jobs in your body like making bones, pumping blood, and digesting food What is an eukaryotic cell? ○ A cell that contains a nucleus is a eukaryotic cell. ○ The other type of cell is called a prokaryotic cell which is what bacteria cells are. ○ Prokaryotic cells do not contain a nucleus. ○ Eukaryotic cells are found in eukaryotes which includes animals, plants, fungi, and protists ○ Eukaryotic cells also contain many other types of structures (organelles) that perform specific functions within the cell ○ The nucleus is sort of like the “BRAIN’ of the cell What are the two main types of eukaryotic cells? ○ Animal cells are found in animals. This includes humans ○ Plants cells are found in plants What is a cell organelle ○ An organelle is a specialized “organ” within a cell that performs a certain function for the cell What are eukaryotic cell organelles and what are their function ○ The nucleus contains the cell’s genetic material, DNA. It directs all cell activity and controls the size and reproduction. ○ The nucleolus uses RNA to make ribosomes, which the cell uses to make protein ○ The nuclear membrane surrounds and protects the nucleus, it can also be called the nuclear envelope ○ The cell membrane surrounds the cell and controls what may enter or exit the cell, it is selectively permeable, which means that it can control what it lets on and out ○ The cytoplasm is a jelly-like fluid that hold and supports all the organelles between the cell membrane ○ The cytoskeleton provides structural support and helps the cell keep its shape, it is located inside the cytoplasm ○ The lysosome break down waste and recycle old cell parts ○ The mitochondria converts food into usable energy (ATP), that is needed for the cell’s functions ○ The vacuole stores food, water, and waste for the cell, plant cells have more larger vacuoles than animals do ○ The vesicles are small sacs that transport materials in, out, and around the cells ○ Endoplasmic Reticulum, is where proteins are made (protein synthesis) and transported around the cell, rough endoplasmic reticulum (RER) contains ribosomes and is the site of protein synthesis, smooth endoplasmic reticulum (SER) does not contain ribosomes, and is responsible for the transport of materials ○ The ribosomes synthesize (make) proteins, they are found either floating around the cytoplasm or attached to the rough endoplasmic reticulum ○ The golgi apparatus packages proteins and lipids molecules that need to be sent out of the cell What makes plant and animal cells different ○ Plant cells contain two additional types of structures ○ The chloroplasts convert light energy from the sun to glucose for chemical energy (photosynthesis) ○ The cell wall surrounds the cell membrane in plant cells, it protects the cell ➔ Cellular Transport ◆ Types of Solution Solute- The substance that is being mixed in the solvent Solvent- The substance that dissolves the solute, forming a solution Solution- A mixture of a solute and solvent ◆ What is concentration? Concentration is the amount of a solute present in a given volume of solution. It describes how much of the solute is dissolved in the solvent ○ High concentration is when there is a high amount of solute in the solution ○ Low concentration is when there is a small amount of solute in the concentration. ◆ Concentration Gradient Molecules like to move around, so they can reach the state of equilibrium, this is when the concentration of molecules is the same throughout the space, this is also referred to as moving down the concentration gradient ◆ What is Passive Transport Passive transport is when molecules move across the cell membrane without the use of ATP (energy) It is when molecules move from high concentration to low concentration to reach equilibrium ◆ Osmosis Osmosis is a type of passive transport only for water molecules, it is when water moves through a semipermeable membrane, from an area of high concentration to low concentration, without using ATP ◆ What is tonicity? The ability of a solution to cause water to move in or out of a cell by osmosis. It depends on the concentration of solutes relative to the concentration inside the cell There are three types of osmosis ○ Isotonic Solution: The concentration of solutes is equal inside and outside the cell, water is moving in and out at the same rate, keeping the cell size stable. This is good for animal cells, but okay for plant cells ○ Hypotonic Solution: The concentration of solutes is lower outside the cell, so water moves into the cell, which can cause the cell to swell or burst. This is good for plant cells but terrible for animal cells. ○ Hypertonic Solution: The concentration of solutes is higher outside the cell, so water moves out of the cell, causing it to shrink. This is bad both for animal cells and plant cells. ◆ Diffusion The movement of molecules from an area of high concentration to an area of low concentration, this process does not require energy ◆ Simple Diffusion Occurs with small or nonpolar molecules, like oxygen and carbon dioxide, because they can move directly through the lipid bilayer of the membrane ◆ Facilitated Diffusion A type of diffusion, where larger or polar molecules like glucose, move across the cell membrane with the help of protein channels. These proteins act like channels or carriers to help move molecules pass through the membrane, however it still moves from high to low concentration without using energy ◆ Active Transport Active transport is the movement of molecules against their concentration gradient, from low concentration to high concentration This process requires ATP and transport proteins, to move substances across the cell membrane ◆ Endocytosis Endocytosis is a process where the cell engulfs substances by folding it membrane around them forming a vesicle that brings the material inside the cell, this can occur for larger molecules or particles thats cannot pass the membrane on their own There are two types of endocytosis ○ Phagocytosis: Where large particles, like bacteria are engulfed ○ Pinocytosis: Where the cell takes in fluid and dissolved substances ◆ Exocytosis The process where substances inside the cell are released to the outside, this happens when a vesicle containing the material fuses with the cell membrane and expels the contents of the cell. ➔ Photosynthesis and Cellular Respiration ◆ Photosynthesis The process by which plants make their own food using carbon dioxide, water, and sunlight Occurs in plant leaves ◆ Chloroplast SIte of photosynthesis in plant cells Chlorophyll in the chloroplasts absorb light ◆ Stomata Guard cells on the underside of leaves Open and close to let CO2 (Carbon dioxide) and O2 (Oxygen) out ◆ Photosynthesis converts light into usable chemical energy ○ Plants take in CO2 and H2O ○ The energy splits H2O molecules ○ The split H combines with CO2 to for C6H12O6 (Glucose) ○ O2 is a waste product ◆ Reactants H20 (Water) C02 (Carbon dioxide) Sunlight energy ◆ Products Plants use the carbon to build their own bodies ○ C6H12O6 (Glucose) ○ O2 (Oxygen) are released from leaves to the atmosphere ◆ Photosynthesis Equation 6H2O+6CO2+ Sunlight Energy = 6O2+C6H12O6 ◆ Factors that Affect the Rate of Photosynthesis Temperature Light Intensity (up to a point) Carbon Dioxide Concentration ◆ Cellular Respiration Animal and plant cells break down organic molecules (glucose) to release energy for use in the cell Cellular Respiration occurs in the mitochondria ◆ Reactants Glucose is obtained from the food you eat Oxygen is obtained from the air you breathe in When you body is ready to release the energy from food you eat, the oxygen breaks in down ○ The glucose molecule is broken down into hydrogen and carbon dioxide ○ The hydrogen molecules form bonds with the oxygen we breathe in, forming water ◆ Products Carbon dioxide is the waste product (what we breathe out) Water Adenosine Triphosphate (ATP) carries energy in the body ◆ Chemical Energy The breakdown of ATP releases energy for powering cell activities Releases energy when the bond is broken between the 2nd and 3rd phosphate. This new molecule is Adenosine Diphosphate (ADP) ◆ Cellular Respiration Equation 6O2 + C6H12O6 = 6H2O + 6CO2 + 36ATP ◆ Conservation of Energy and Matter In this complementary reaction, matter is cycled. The atoms are just rearranged Matter and Energy cannot be created nor destroyed ◆ Short Term Carbon Cycle Carbon flows between plants, animals, atmosphere, and soil Photosynthesis and Cellular Respiration are opposite processes that help carbon to cycle ◆ Aerobic and Anaerobic Respiration Aerobic Respiration ○ All living things break down sugars (glucose) to get their energy. This is usually an aerobic process with oxygen. ○ When we exercise: initially the body supplies the working muscles with oxygen Anaerobic Respiration ○ When we work out intensely or for extended periods the oxygen content in cells is decreased to the point where aerobic respiration cannot occur ○ Your body switches to anaerobic respiration (without oxygen) ➔ Aerobic and Anaerobic Respiration ◆ Respiration Cells need energy for active transport This energy is released by ATP being broken down There are two types of respiration ○ Aerobic respiration which requires oxygen ○ Anaerobic respiration which does not require oxygen ◆ Aerobic Respiration Aerobic respiration requires oxygen. It has 2 main stages ○ Stage 1: Glycolysis ◆Takes place in the cytoplasm ◆This stage does not require oxygen ◆2 ATP molecules are produced for every molecule of glucose ○ Stage 2: Cellular Respiration ◆Takes place in the mitochondria ◆Total ATP = 38 ATP ○ Anaerobic Respiration ◆Anaerobic respiration does not need oxygen ◆It is also called fermentation ◆When oxygen isn’t available, pyruvate can’t be broken down. This can happen during physical exercise Stage 1: Glycolysis ○ Takes place in the cytoplasm ○ Total ATP = 2 ATP Stage 2: Fermentation ○ Takes place in the cytoplasm ○ In animals it produces lactic acid ○ In plants it produces CO2 and ethanol ◆ Comparison of the 2 types of respiration Aerobic goes through cellular respiration, while anaerobic goes through fermentation Anaerobic respiration has 4 ATP total while aerobic respiration has 38 ATP total ➔ Cell Division ◆ Cell Division Why do cells divide? ○ Reproduction ○ Growth ○ Repair How does the cell know how to divide? ○ The DNA in the nucleus has the instructions for all of the cell’s activities ◆ Cell Cycle The series of events that cells go through as they grow and divide The cell cycle is the life of the cell from the time it is first formed from a diving cell until it’s own division into two cells Interphase ○ Cell Grows -G1 ○ Cell makes exact copy of DNA (replication) -S Phase ○ Synthesis of new organelles like mitochondria, ribosomes, etc -G2 ○ The cell spends most of its time in interphase ○ Mitosis -Division of nucleus ○ Cytokinesis -Division of cytoplasm ◆ Mitosis Mitosis is the division of a body cell to make 2 new body cells with the same genetic material There is only one division that creates 2 new cells that are identical to the first cell In humans, each daughter cell has 46 chromosomes Prophase ○ Chromatin in nucleus condense and chromosomes form Metaphase ○ Chromosomes line up in the middle of the cell Anaphase ○ New chromosomes move to opposite ends of the cell Telophase ○ New nuclear membrane forms around each new region of chromosomes ◆ Cytokinesis Cell membrane pinches in around the middle of the cell The cell splits in two Each daughter cell ends up with an identical set of chromosomes ◆ Meiosis Meiosis is the division of sex cells to make 4 new sex cells that contain half the original DNA as the beginning cell There are two cell divisions creating 4 unique daughter cells ○ Sperm -male sex cells ○ Egg- female sex cells In humans, each sex cells has 23 chromosomes ➔ Levels of Organization ◆ Levels of Organization There are 5 levels of organization in a multicellular organism ○ Cell, Tissue, Organ, Organ Systems, Organism ◆ Cells The most basic unit of structure and function of all living things Cells are extremely small and require the use of a microscope in order to view them Robert Hooke -credited with the discovery of the cell Anton van Leeuwenhoek -first person to observe living cells Examples of Cells: ○ Onion Skin Cells ○ Red Blood Cells ○ Muscle Cells ◆ Tissues Group of similar cells performing the same function Examples of Tissues ○ Connective -connects, supports, or surrounds other tissues or organs ○ Epithelial -covers body surfaces, body cavities, and organs ○ Muscular -compose muscles that can contract to produce movement ○ Nerve -composed of cells that receive stimuli and conduct impulses in the body ◆ Organs A group of tissues that work together to perform a specific function There are 78 organs in the human body 5 vital organs -brain, heart, kidneys, liver, and lungs Examples of organs ○ Brain ○ Lungs ○ Heart ◆ Organ Systems A group of organs that work together to perform a specific function There are 11 organ systems in the human body Examples of organ systems ○ Circulatory system ○ Respiratory system ○ Skeletal system ◆ Organisms A living individual that can reproduce, grow, and maintain homeostasis Can belong to any of the 6 kingdoms of life Scientists estimate there are about 8.7 million species of organisms on Earth Examples of Organisms ○ Badger ○ Penguin ○ Ostrich ➔ Human Body Systems ◆ Cardiovascular System Functions: ○ Delivering needed materials like nutrients and O2 to other body cells ○ Removing wastes such as CO2 from other body cells ○ Fighting disease by transporting cells that attack disease causing microorganisms Heart ○ Muscular organ that pumps the blood to through the circulatory system ◆4 parts of the heart: right ventricle, left ventricle, right atrium, left atrium Arteries ○ Blood vessels that distribute oxygen-rich blood to your entire body Veins ○ Blood vessels located throughout your body that collect oxygen poor blood and return it to you heart Superior Vena Cava ○ A large significant vein responsible for returning deoxygenated blood collected from the body to the right atrium Inferior Vena Cava ○ Your body’s largest vein, carries oxygen depleted blood back to your heart from the lower part of your body Aorta ○ Large, cane shaped vessel that delivers oxygen-rich blood to your body Blood ○ The fluid that circulates in the heart, arteries, capillaries, and veins of a vertebrate animal carrying nourishment and oxygen to and bringing away waste products from all parts of the body Plasma ○ The liquid portion of blood Capillaries ○ Small blood vessels that the exchange of materials between the blood and tissue cells Red Blood Cells ○ Carry oxygen from the lungs and deliver it throughout our body White Blood Cells ○ They protect you against illness and disease Platelets ○ Small, colorless cell fragments in our blood that form clots and stop or prevent bleeding ◆Respiratory System Function: ○ The ability to breathe ○ Transfers O2 and CO2 into and out of the blood Lungs ○ Two organs that remove oxygen from the air and pass it into your blood Trachea/Windpipe ○ Passage connecting your throat and lungs Nose ○ Openings that pull air from outside your body into your respiratory system Bronchi ○ Small branches of the bronchial tubes that lead to the alveoli Alveoli ○ Tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place Diaphragm ○ Muscle that helps your lungs pull in air and push it out ◆Digestive System Functions ○ Break down food ○ Stores food ○ Moves the waste along to the excretory system Mouth ○ Where mechanical digestion (chewing) and chemical digestion (saliva) begin Esophagus ○ Receives food from the mouth and connects to the stomach Stomach ○ Hollow organ, or "container," that holds food while it is being mixed with stomach enzymes Liver ○ Process the nutrients absorbed from the small intestine using bile Small Intestine ○ Made up of three segments — the duodenum, jejunum, and ileum — the small intestine is a 22-foot long muscular tube that breaks down food using enzymes Large Intestine ○ The large intestine is fatter than the small intestine and it's almost the last stop on the digestive tract Rectum ○ Holds stool for elimination Mechanical Digestion ○ Food broken down through chewing Chemical Digestion ○ Uses water and digestive enzymes to break down the complex molecules Villi ○ Microscopic finger-like projections inside the small intestine that increase the amount of nutrients absorbed from food ◆Excretory System Functions ○ Removes metabolic wastes from cells ○ Removes waste from the body Bladder ○ Sac-like structure with muscular walls that holds urine Kidney ○ Paired, bean-shaped organs located in the abdomen. The kidneys take the majority of cellular waste from the body, transported to them via the bloodstream. They then produce urine and send it to the bladder for excretion Ureter ○ Tube that carries urine from the kidney to the bladder Liver ○ Main detoxifying organ of the body Lungs ○ Carbon dioxide is a waste product that is removed from the cells and transferred to the bloodstream.When the blood reaches the gills or lungs, it is exchanged for oxygen and released Skin ○ Secondary excretory organ since sweat glands in the dermis can remove salts and some excess water Nephron ○ Basic filtering unit of the kidney. It removes water and water and waste from the blood ◆Nervous System Functions ○ Monitors all the stimuli inside and outside the body ○ Send messages to and from the brain to the body ○ The nervous system is responsible for regulating and maintaining homeostasis Brain ○ Controls most functions in your body Spinal Cord ○ A long bundle of nerves inside your spinal column Central Nervous System ○ Your brain and spinal cord Peripheral Nervous System ○ Consists of many nerves that branch out from your CNS all over your body. This system relays information from your brain and spinal cord to your organs, arms, legs, fingers and toes Sensory Nerves ○ Carry signals to your brain to help you touch, taste, smell, and see Motor Nerves ○ Carry signals to your muscles from your brain to help you move Neuron ○ Basic unit of the nervous system ◆Muscular System Function ○ Responsible for movement through contractions (voluntary and involuntary) Muscle ○ Contractions/Movement Smooth Muscle ○ Found in internal organs and consists of involuntary movement Skeletal Muscle ○ Also known as striated muscle; work with tendons, ligaments, and bones Cardiac Muscle ○ Line the walls of your heart, responsible for making your heart contract/beat Involuntary ○ Movements that occurs unconsciously Voluntary ○ Controlled, intengional, the movement of muscles (lifting your arm) ◆Skeletal System Function ○ Provide Structure ○ Movement ○ Protect internal organs Bones ○ Made of living tissue that can grow, give our bodies structure and shape, made with 4 layers of tissues Cartilage ○ Soft and flexible connective tissue that is used to connect and protect bones Ligaments ○ Connective tissue that hold bones together at the join Tendons ○ Connective tissue that connects muscle to bone Joints ○ Where two bones meet, some joints move, some don’t move (fixed joints like in the skull) Skull ○ Protects the brain, different bones fused together with special joints called sutures Spine ○ Bone that runs down your back; allows for twisting and bending and hold upright; protects the spinal cord Ribs ○ 12 pairs of bones connected to the spine; protects the lungs, heart, and liver Arms/Hands ○ Allows for movement for arms and grasping/pulling/pushing ; scapula, humerus, radius and ulna Legs/Feet ○ Allows for bending and moving; supports the weight of the body ◆Integumentary System Functions ○ Protects body tissues against injury ○ Helps regulate body temperature ○ Provides sense of touch Epidermis ○ Top layer of the skin. It is a waterproof layer that is responsible for skin color. New Cells are pushed upward from the bottom ◆Melanin Gives skin its color and protects against UV rays Dermis ○ Second layer of the skin. Contains nerves, blood vessels, sweat & oil glands ◆Sebaceous (oil) glands Helps protect the skin ◆Sweat Glands Produce perspiration (sweat) to cool the body Subcutaneous Layer ○ Deepest layer of the skin. Contains connective tissue, blood vessels & fat cells. Keeps the body warm and absorbs shock Hair ○ Modified epidermis. Helps trap heat near skin Nails ○ Thickened & hardened epidermis ◆Immune System Function ○ Helps protect the body against disease Tonsils ○ Stops germs from entering through the body, mouth, or nose Lymph Nodes ○ Filter lymph, trapping bacteria and other disease-causing microorganisms Spleen ○ Stores various immune system cells, breaks down red blood cells, stores and breaks down platelets Lymph Vessels ○ Part of the cardiovascular system, connect to large veins in the chest Thymus ○ T- Cells mature here Mucous Membranes ○ The immune system cells are directly beneath the mucous membranes where they prevent bacteria and viruses from attaching Skin ○ Provides the first line of defense against germs entering from the outside of the body B Cells ○ A type of white blood cell that makes antibodies Lymphocytes ○ White blood cells that distinguish between different types of pathogens (organisms that cause disease) Thymus cells: T cells are thymus cells and move through the body and constantly monitor the surfaces of all cells for changes ◆Endocrine System Function ○ Releases hormones into the bloodstream ○ Helo control mood, growth, and development, the way our organs work. metabolism, and reproduction ○ Regulates how much of each hormone is released Hormones ○ Chemical messengers in the body Metabolism ○ Conversion of nutrients into the energy that the body needs Pancreas ○ Produces insulin which controls blood sugar levels Negative Feedback System ○ When hormones in the blood reach a certain level the endocrine system signals to stop the release of that hormone. Works like a thermostat ◆Lymphatic System Function ○ Collect extra lymph & fluid from body tissues and return it to the blood ○ Fight infection Lymph ○ Clear, watery fluid that contains proteins, salts, and other substances Lymph Nodes ○ Filter germs and damaged cells from the lymph Spleen ○ Clearing worn-out red blood cells and other foreign bodies (such as germs) from the bloodstream ◆Reproductive System Function ○ Provide for the continuation of a species Gametes ○ Sex cells (sperm & egg) Testes ○ Produce sperm cells & testosterone (hormone) in males Ovaries ○ Produce egg cells & estrogen (hormone in females) Fertilization ○ When a sperm cell combines with an egg cell Zygote ○ Fertilized egg cell

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