BIO 212 Unit 1 Chapter 2 Study Guide

• Study guide for BIO 212, Unit 1.

Chapter 2

• An element consists of only one type of atom, like hydrogen or oxygen.
• A compound contains two or more different elements chemically bonded, such as water (H2O).
• The four elements that make up 96% of living matter consist of oxygen, carbon, hydrogen, and nitrogen.
• Atoms have a nucleus made of protons and neutrons, surrounded by an electron cloud.
• Atomic number refers to the number of protons.
• Mass number is the sum of protons and neutrons in an atom's nucleus.
• Atomic weight is the relative weight given to an element.
• Valence is the outermost electrons.
• Neutrons are derived by subtracting the atomic number from the mass number.
• Radioactive isotopes can date fossils using their decay rates.
• Radioactive isotopes trace atoms in metabolism.
• An atom with a complete outer shell is unreactive.
• An atom with an incomplete shell is chemically reactive.
• Nonpolar covalent bonds share electrons equally, as with atoms of similar electronegativities, like O2.
• Polar covalent bonds share electrons unequally, creating partial charges, such as H2O.
• Ionic bonds involve electron transfer, forming ions when there is a large electronegativity difference, such as NaCl.
• Weak bonds help build and support vital molecules, enabling flexibility, movement, cell membrane shaping, and water regulation.
• Hydrogen bonds form when a hydrogen atom covalently bonded to N, O, or F attracts another electronegative atom.
• Van der Waals interactions are weak and caused by temporary shifts in electron distribution.
• Hydrogen bonds are stronger
• Van der Waals forces are weaker and affect all molecules, even nonpolar ones.

Chapter 3

• Water regulates temperature by stabilizing climates and body temperature due to its high specific heat.
• Water's cohesion and adhesion aid water transport in plants and create surface tension.
• Universal solvent to dissolve nutrients and gases for biological processes.
• Ice floats, which insulates aquatic life
• Evaporative cooling regulates body and environmental temperatures.
• Water is needed for photosynthesis and cellular respiration.
• Water acts as a buffer to maintain balanced conditions (pH stability).
• Oxygen is more electronegative, making water polar.
• Water's bent shape and partial charges lead to hydrogen bonding.
• Partial charges allow water molecules to form hydrogen bonds because oxygen is highly electronegative.
• Cohesion, adhesion, high specific heat, and the fact that ice floats are four emergent properties of water resulting from hydrogen bonding.
• Cohesion of water aids in water transport in plants and creates surface tension.
• Water's high specific heat stabilizes ocean and body temperatures.
• Water's expansion prevents bodies of water from completely freezing.
• A solute is a dissolved substance.
• A solvent is a liquid that dissolves a solute.
• A solution is a mixture of solute and solvent.
• Water's polarity allows it to dissolve ionic and polar substances, making it a versatile solvent.
• Hydrophilic substances include polar and ionic compounds which love water.
• Hydrophobic substances are water hating.
• 2H2O=H3O++OH- symbolizes the equation for the dissociation and re-formation of water.
• Acids (pH<7) donate H (ex vinegar).
• Bases (pH>7) accept H (ex bleach)
• Buffers resist pH changes

Chapter 4

• Carbon's bonding forms 4 covalent bonds, allowing diverse molecular structures
• Straight, branched, or rings, leading to diverse organic molecules
• Hydroxyl - polar, in alcohols
• Carboxyl- acidic, in amino acids
• amino- basic, in proteins.
• Phosphate- Energy transfer (ATP)

Chapter 5

• Carbohydrate, Lipids, proteins -CHO.
• Proteins, nucleic acids- CHON.
• nucleic acids- CHONP
• Carbohydrates- monosaccharide (glucose)
• Lipid- Glycerol+fatty acids
• Proteins- Amino acids
• Nucleic acids - nucleotides
• Dehydration- links monomers, removes water
• Condensation- Breaks polymers, adds water
• Carbohydrate- Glycosidic linkage
• Lipids- Ester linkage
• Proteins- Peptide bond
• Nucleic acids- Phosphodiester bond
• Carb- Bread
• lipid-butter
• Protein-meat
• Carb- provides quick energy and structural support.
• Lipid-store long-term energy, form cell membranes and act as signaling molecules.
• Proteins- perform structural, enzymatic, transport and immune functions.
• Nucleic acids- store and transmit genetic information
• Carbohydrate: glycosidic linkage
• Lipid: ester linkage
• Protein: peptide linkage
• Nucleic Acid: phosphodiester linkage
• Starch- energy storage in plants.
• Cellulose structural(plant cell walls)
• Glycogen- energy storage in animals
• Saturated- No double bonds solid at room temp.
• Unsaturated- double bonds liquid at room temp.
• Polar, nonpolar, electrically charge (acid, basic +Charge)
• Primary- amino acid sequence.
• Secondary- alpha helices and beta sheets.
• Tertiary- 3D shape.
• Quaternary- multiple polypeptides
• They store genetic information (DNA/RNA)

Chapter 6

• Prokaryotic- no nucleus, no membrane- bound organelles (bacteria).
• Eukaryotic- has nucleus, organelles (plants, animals)
• Double membrane with pores for RNA transport
• Be able to label the major structures in prokaryotic, plant and animal cells
• Cytomembranous system (nuclear membrane, ER, vesicles and Golgi apparatus).
• Know the general structure and function of ribosomes, mitochondria, and chloroplasts
• the cytoskeletal system in relation to their relative size, composition, and function
• the different type of intercellular junctions