BIO EXAM 1 PDF

**Study guide 1: Lecture (1-9)** What are major themes in biology that unite all life? Evolution: All living things are connected through a common ancestor, and species adapt over time. Structure and Function: The structure being how something is built and the function being how it helps do its j...

**Study guide 1: Lecture (1-9)** What are major themes in biology that unite all life? Evolution: All living things are connected through a common ancestor, and species adapt over time. Structure and Function: The structure being how something is built and the function being how it helps do its job Example: A bird\'s wings are structured to help it fly Energy and Matter: All living things need energy to survive. Ex: Plants use sunlight (photosynthesis) Ex: Animals ear food for energy Information Flow: DNA is the instruction manual for life, it passes info from parents to offspring (child) Interactions: Living things interact with each other and their environment. Bees pollinate flowers, helping plants reproduce. What does it mean to study life at different levels of organization? Molecule: DNA or proteins that build life Cell: The smallest unit of life Tissues: Groups of similar cells working together Organism: One individual living thing Population: a group of the same species living together Ecosystem: All the living and nonliving things in an area Ex: If you study how your heart works, you\'re looking at the organism level. If you study how humans affect forests, you\'re studying at the ecosystem level. What is common information among all life: DNA: all living things use DNA as their genetic material. It carries instructions for building and running the organism. Ex: Both humans and bacteria have DNA, but the instructions in human DNA are more complex Cells: All living things are made of cells, whether it\'s one (bacteria) or many (humans) What is the significance of the transfer of energy? Life needs energy to do anything: move, grow, reproduce Ex: Energy flow starts with the sun; plants absorb sunlight and convert it into energy through photosynthesis Ex: Animals eat plants or other animals to get energy Ex: A lion eats a zebra, getting energy that originally came from plants the zebra ate. How are interactions important to understanding biology? Interactions between organisms: Predators hunt prey Interaction as organism: Braint ells your muscles to move Interaction with the environment: Tress absorbs carbon dioxide and release oxygen, which animals breathe in. What is evolution? Why is it significant for studying ALL biology? Evolution: The process by which species change over time due to natural selection. Significance: It helps us understand relationships between species and how they\'ve adapted to survive. Ex: Giraffes evolved long necks to reach high leaces on trees, giving them an advantage. What is the unity of life? All living things share certain traits DNA: The same genetic material Cells: All organisms are made of cells. Common ancestor: All species, no matter how different, evolved from a single ancient organism. Ex: Even though a whale and a sunflower are very different, they both have DNA and use energy to survive. What are matter, elements, and compounds? Matter: Anything that has mass and takes up space (like water, air, and your desk. Elements: Pure substance made of only one type of atom (hydrogen, oxygen, carbon) Compounds: Substances made of two or more elements chemically combined (water, H2O) What are the 4 top essential elements for life? Carbon Hydrogen Oxygen Nitrogen What makes trace elements important? Example? Trace elements are needed in tiny amounts but are essential for survival Iron Fe: helps carry oxygen in your blood Iodine I: Helps your thyroid gland work proper Describe an atom? What are the parts of an atom? Protons: positive charge, found in the nucleus Neutrons: No charge, also in the nucleus Electrons: Negative charge, orbit around the nucleus Ex: In a hydrogen atom, there is 1 proton and 1 electron but no neutrons Are you able to identify the mass number and atomic number for an element? Atomic number: Number of protons in an atom (hydrogen has 1 proton so its atomic number is 1) Mass number: Total number of protons and neutrons Isotopes: Atoms of the same element with different numbers of neutrons (carbon 12 and Carbon 14 both are carbon but have different neutron counts) How is the period table arranged? What information does it convey? Arranged by atomic number (number of protons) It shows: Atomic number Symbol (O, H, S) Atomic mass Elements in the same column have similar chemical properties (like helium and neon) Going down is groups Going across is periods What are valence shells? How do they function with respect to energy? How do they affect the "chemical behavior" of an atom? Valence shells: The outermost shell of electrons in an atom Atoms are stable when their valence shell is full What are ions and how do they form? Describe the two types of ions. Ions: Atoms that gain or lose electrons and have a charge Types: Cations: Positively charged (lose electrons) (Sodium Na+) Anions: Negatively charged (gain electrons) (Chloride Cl-) What is electronegativity and why is it important? Electronegativity: How strongly an atom pulls electrons towards itself. On a periodic table it\'s from left to right and from down to up for how strong Determines how atoms bond Oxygen for example is very electronegative which is why it pulls electrons in water because H is not very electronegative What is a molecule? A group of two or more atoms bonded together example O2 or H2O Describe the different types of chemical bonds? Do they share electrons or not? Covalent bonds: share electrons, also two nonmetals for example (H2O) Ionic Bonds: Transfer electrons, metal and non-metal, example NaCl Hydrogen bonds: Week attractions between molecules, between water molecules What makes a molecule polar? A polar molecule has uneven sharing of electrons (if the electronegativity is greater than 0.4 it\'s a polar bond) Water is polar because oxygen pulls electrons more strongly than hydrogen Why are chemical bonds important for understanding chemical reactions? Chemical reactions happen when bonds are broken or formed When you digest food, bonds are the food broken to release energy. Know what it means for water to be a polar molecule. Water is polar because it has a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atoms That means oxygen pulls electrons more strongly than hydrogen creating an uneven distribution of charge because oxygen is more electronegative. What kinds of bonds hold different water molecules together? Hydrogen bonds: weak bonds between the slightly positive hydrogen of one water molecule and the slightly negative oxygen of another Describe how water molecules stick together and to other surfaces? Cohesion: Water molecules stick to each other (due to hydrogen bonds) Adhesion: Waer molecules stick to other surfaces Explain how hydrogen bonds in water help contribute to specific heat and heat of vaporization stabilizing temperature? Describe how this is important for life Specific heat: Water absorbs a lot of heat before its temperature rises, due to hydrogen bonds. This stabilizes climate and body temperature. Oceans regulate the earth\'s temperature Heat vaporization: Water takes a lot of energy to evaporate. This cools surfaces, like sweat cooling your skin. Why does ice float on liquid water? What are the changes to the H bonds? In ice hydrogen bonds form a rigid structure, making it less dense than liquid water. Thats why it floats. Can you identify which is the solvent verses the solute in a solution? Solvent: Is the substance that dissolves something else (ex: water) Solute: Is the substance that gets dissolved (ex: salt) What are the main properties of molecules that are hydrophilic vs hydrophobic? Hydrophilic: Attracted to water (salt sugar) Polar molecules dissolve easy in water Hydrophobic: Repels water (oils fats) Nonpolar molecules do not dissolve in water What does it mean to measure a solutes concentration? Concentration: Is how much solute is dissolved in a given amount of solved A cup of salty water has a higher salt concentration than a teaspoon of salty water How many molecules in a mole of glucose? What about a mole of anything? A mole is 6.022 x 10\^23 molecules (Avogadro\'s number) A mole of glucose has 6.022 x 10\^23 glucose molecules Why does concentration matter for bio? It affects how nutrients is absorbed in cells It efficiently enzyme work in chemical reactions Explain why understanding ions is important for understanding acidity? Acidity is based on the concentration of hydrogen ions (H+) in a solution More H+ means more acidic, fewer H+ means more basic What does acidic and basic mean? How do you measure that? If a solution has a pH of 3, how much more acidic is it than another solution with a pH of 6? What does that mean in terms of how many more H+ it has? Acidic: pH less than 7 (more H+) Basic: pH greater than 7 (less H+) PH scale: Each number is 10x more/less acidic A solution with ph3 is (10 x 10 x10) times more acidic than pH6 What are buffers and how do they work? Buffers help maintain a stable pH by absorbing or releasing H+ ions Blood contains buffers to keep its pH around 7.4 What does it mean for a compound to be "organic"? Organic compounds contain carbon atoms bonded to hydrogen and often to oxygen, nitrogen, or other elements. Glucose (C6H12O6) is organic How many covalent bonds can carbon form? Carbon can form 4 covalent bonds, allowing it to create large, complex molecules like DNA and proteins. How does a double bond (or even a triple bond) limit a molecules structure? Double and triple bonds make a molecule rigid, preventing rotation around the bond. In ethylene (C2H4) the double bond keeps the molecule flat. Can you recognize hydrocarbons and describe how hydrocarbons interact with water? Hydrocarbons: are molecules made of carbon and hydrogen Methane (CH4) is a hydrocarbon Hydrocarbons are nonpolar and hydrophobic (don\'t mix with water) Oil Describe the four ways molecules diversity arise from a carbon backbone? Molecules differ by: Length: Carbon chains can be short or long Branching: Chains can be straight or branched Double bonds: The presence and location of double bonds change the molecule. Rings: Carbon atoms can form ring structures. (glucose is ring shaped) What is isomer a? Isomers are molecules with the same chemical formula but different structures Glucose and fructose both have the formula, but their atoms are arranged differently. What are the three kinds of isomers? Can you recognize them? Structural isomers: Different atom arrangements Cis trans isomers: Same bonds but different spatial arrangements Enantiomers: Mirror images of each other Hands are like enantiomers same structure but mirrored List the 7 functional groups most important for life? Hydroxyl (-OH): found in alcohols Carbonyl (C=O): Found in sugar Carboxyl (-COOH): Found in acids like vinegar Amino (-NH2): Founds in amino acids Sulfhydryl (-SH): Found in proteins Phosphate (-PO4): Found in ATP (energy molecule) Methyl (-CH3): Affects gene expression Describe the properties of these functional groups? Polar vs Non-Polar: Hydroxyl is polar, and methyl is nonpolar Hydrophilic vs hydrophobic: Polar groups are hydrophilic, nonpolar groups are hydrophobic Acid/Base: carboxyl is acidic amino is basic What is the difference between a ketone and an aldehyde? Both have a carbonyl group (C=O) Ketone: Carbonyl is in the middle of the molecule Aldehyde: Carbonyl is at the end of the molecule. What makes methyl groups different from other functional groups? Methyl groups (-CH3) are nonpolar and hydrophobic. They affect molecular shape and gene activity, unlike other functional groups that are often polar and reactive. Recognize monomers vs polymers Monomers: Small building blocks Glucose is a monomer of carbohydrates Polymers: Large molecules made by linking monomers Starch is a polymer made of glucose Describe how dehydration and hydrolysis work. Dehydration: Joins monomers by removing water Linking amino acids to make proteins Hydrolysis: Breaks polymers into monomer by adding water. Breaking down starch into glucose during digestion Describe the basic structure and function of carbohydrates How do sugar molecules vary? By the number of carbons and the arrangement of atoms (glucose and fructose are isomers (same formula different structures)) What is the covalent bond between monosaccharides called? Glycosidic bond What are different examples of polysaccharides? How do structure differ? Starch: Energy storage in plants Glycogen: Energy storage in animals (liver/muscles) Cellulose: Structural support in plant cell walls (not digestible by humans) What is monomer of nucleic acids? What is it made of? Monomer: Nucleotide Made of: A sugar (deoxyribose in DNA, ribose in RNA), a phosphate group, and a nitrogenous base. Compare DNA to RNA: DNA: Double stranded, uses thymine (T) RNA: Single stranded, uses uracil (U) Categories of nitrogenous bases: Purines: Adenine (A), Guanine (G)- Double rings Pyrimidines: Cytosine (C), Thymine (T), Uracil (U)- single ring What is the basic structure of a protein? How do amino acids differ? Structure: Made of chains of amino acids (monomers) Joined by peptide bonds How to amino acids differ? Their R group (side chain) Some R groups are polar (hydrophilic), nonpolar (hydrophobic), or charged What defines the N- and C- terminus of a polypeptide? N-terminus: end with the amino group (-NH2) C terminus: End with the carboxyl group (-COOH) Describe the three types of lipids and their properties. Fats: Made of glycerol and fatty acids Saturated fats: No double bonds, solid at room temp (ex: butter) Unsaturated fats: Have double bonds, liquid at room temp (ex: olive oil) Phospholipids: Structure: Two fatty acids + a phosphate group. Hydrophilic head and hydrophobic tails make up cell membranes Steroids: Structure: Four fused carbon rings Ex: cholesterol, hormones like estrogen/testosterone What are the three components of cell theory? All living things are made of cells Cells are the basic unit of life All cells come from pre-existing cells Why are cells small? Explain why the surface area to volume ratio is important. Small cells have a high surface area to volume ration, which allows for faster exchange of material (like nutrients and waste) with their environment. What Kinds of microscope would you use for studying. A pencil tip would be a light microscope A mitochondrion would be an electron microscope (detailed structures) A virus: Electron microscope (viruses are extremely small) What are common features of all cells? Cell membrane, cytoplasm, DNA, and ribosomes What are the three domains of life? Bacteria (prokaryotes), archaea (prokaryotes), and Eukarya (eukaryotes like plants and animals and fungi) What are the main parts of a prokaryotic cell? Prokayotic cells: No nucleus, smaller than eukaryotic cells Key parts: Nucleoid (where DNA is located), ribosomes, cell membrane, and sometimes a cell wall or flagella What is an advantage to cell membranes and compartmentalization in eukaryotic cells? Compartmentalization allows different parts of the cell to specialize and perform specific functions efficiently Ex: mitochondria for energy production Which domains have a prokaryotic cell type? Eukaryotic cell types? Prokaryotic: Bacteria and archea Eukaryotic: Eukarya Describe the parts of the nucleus. Nuclear envelope: Double membrane with pores for material exchange Nucleolus: Makes ribosomal RNA Chromatin: DNA + proteins that form chromosomes Where ribosomal subunits assembled? In the nucleolus What is the main function of ribosomes? Where are they found? Ribosomes make proteins Found in the cytoplasm or attached to the rough ER What defines whether an organelle is part of the endomembrane system? Organelles involved in making, modifying, and transporting proteins and lipids Ex: ER, Golgi apparatus, lysosomes, vesicles Describe the endomembrane system and its parts. Rough ER: has ribosomes, makes proteins. Smooth ER: Makes lipids, detoxifies substances Golgi apparatus: Modifies and ships proteins/lipids Vesicles: Transport materials How does smooth ER differ from rough ER? Rough ER has ribosomes and makes proteins. Smooth Er lacks ribosomes and makes lipids Why is it important to have cis and trans sides of the Golgi apparatus? Cis side: Receives materials Trans side: Ships materials out What are the different functions of lysosomes? How is this an example of the importance of compartmentalization? Lysosomes digest food, recycle organelles, and destroy harmful invaders. Their enzymes are contained, so they don\'t harm the rest of the cell. Describe autophagy and phagocytosis Autophagy: Recycling worn out organelles Phagocytosis: Engulfing large particles or invaders (ex: by white blood cells) What are vacuoles and how do they function? Storage compartments for water, nutrients, or waste/ Ex: plant cells have large vacuoles for storing water Describe the theory of endosymbiosis. What kind of evidence do we see? Theory: Mitochondria and chloroplasts were once free-living bacteria Evidence: Have their own DNA and ribosomes Double membrane structure What are the important structures of mitochondria and how do they contribute to the function of this organelle? Cristae: Folds in the inner membrane, increase surface area for energy production Matric: Fluid inside, where reactions like the citric acid cycle occur Identify the structures of chloroplast. What is this organelle\'s main function? Structures: Thylakoids (stacked into grana), stroma (fluid) Function: Photosynthesis-converts sunlight into energy What is the cytoskeleton and its function? A network of protein fibers providing structure, movement, and transport within the cell. Recognize the structure and function of the three cytoskeletal filaments. Microfilaments: Actin fibers for movement Intermediate filaments: strength and support Microtubules: Hallow tubes for transport and cell division