AP Biology Semester 1 Study Guide

Natural Selection

Evolution where organisms better adapted to their environment are more likely to survive, reproduce, and pass on specific traits to give other generations better odds at survival

Water properties: Polarity and Charges

Polar= hydrophilic, nonpolar= hydrophobic.

Charges= Water molecules have a partial negative charge on oxygen and a partial positive charge on hydrogens. Due to the unequal electron sharing, making them polar, the Polarity causes attractions caused hydrogen bonds.

Water Properties: hydrogen bonding

A strong inter molecular force where a hydrogen atom contently bonded to a high electronegative atom is attracted to a lone pair of electrons on another nearby electronegative atom. It creates a partial positive charge and is crucial for water’s properties, DNA structure, and protein folding

Dehydration Synthesis

Removal of water which brings molecules together; forms polymers. Makes smaller molecules into bigger ones.

Hydrolysis

addition of water which tears molecules apart; forms Monomers. Breaks larger molecules into smaller ones, so they can diffuse.

Water Properties: Cohesion

Water molecules stick to themselves due to their polar nature and hydrogen bonds. Property is due to the formation of hydrogen bonds between molecules which creates surface tension, and enables capillary action.

Water Properties: Adhesion

The tendency of water molecules to stick or cling to other substances due to attractive forces and hydrogen bonds. This property allows water to rise against gravity in plants and helps in the interaction of water with various materials.

Surface Tension

its surface acts like a thin, elastic skin, allowing it to resist external forces because water molecules stick tightly together due to hydrogen bonds, pulling inward at the surface, creating tension that lets small insects walk on the water or for water to form droplets.

Water density

Most dense: liquid, middle density: solid, least dense: gas

Buffer solutions

Solution that resists changes in pH.

Macromolecules

Lipids, Carbohydrates, Proteins, Nucelic Acids

Lipids- lipids are loners

CHO. Fats, oils, and steroids that store energy and make up cell membranes. Lipids are loners= no true Monomers but made up of fatty acids and glycerol. Look for C=C bonds in unsaturated fats.

Carbohydrates

CHO in 1:2:1 ratio. Provide energy and structural support. Monosaccharides.

Proteins

CHON. Large molecules made up of amino acids, serving as enzymes, structural components, and signaling molecules in organisms. One or more polypeptides. NCC, with R group and acid/carboxyl group.

Nucleic Acids

CHONP or CHON. Polymers made up of nucleotides that store and transmit genetic information, including DNA and RNA.

Protein structure- Structure leads to function

Primary: peptide bonds, Secondary: alpha helix or beta pleated sheets, Tertiary: based on properties, basic, positive, etc., Quaternary: optimal, multiple protein structures combining.

Function is impacted when the primary/Tertiary structure is changed.

How do proteins denature

Excess pH or temperature can break down the structure of a protein

Polar covalent bonds vs nonpolar covalent bonds

Polar covalent bonds involve unequal sharing of electrons between atoms with different electronegativities, leading to a partial charge. Nonpolar covalent bonds involve equal sharing of electrons between atoms with similar electronegativities, resulting in no charge difference.

Passive and active transport

Passive: high to low, doesn’t require energy

Active: low to high, requires ATP energy

NA+/K+ pump (affinity for sodium binding)

Helps maintain resting membrane potential. Low to high= active transport. Electrochemical gradient= charge and ions difference.

Volume of water inside plant cells and animal cells

Plant Cells: lots of water due to vacuole storing water (turgor pressure) and nutrients (want hypotonic solution because of cell wall)

Animal Cells:less than plants because temporary vacuoles for waste/digestion, water fills cytoplasm (want to be isotonic or else it’ll burst)

Hypertonic

higher solute concentration than fluid

Hypotonic

higher fluid concentration than solute

isotonic

same solute concentration as the fluid inside cells

Mitochondria vs Chloroplasts

M- ATP through respiration, break down fuel molecules, cristae, consume O2 and release CO2, more surface area= more energy produced

C- Capture light energy for photosynthesis, internal thylakoids, more surface area of thylakoids= more light reactions, chlorophyll, plants/algae, consume CO2 and release O2.

Kidney filtration

Enzyme Activity

Rate at which an enzyme speeds/slows a chemical reaction ex: metabolism. Factors= temp, pH, concentrations. Optimum conditions= best.

Activation energy

More enzymes lower the activation energy by binding to substrate, stabilizing the transition state, increasing reaction rate without being consumed

Properties of enzymes

Enzymes have specific active sites, lower activation energy, are not consumed in reactions, and can be influenced by temperature and pH.

Activation site + binding to it

Induced model fit NOT lock and key, enzymes dock with substrates.

Competitive inhibition

Another ligand binds to the active site inhibiting the substrate from binding and causing enzyme activity

Noncompetitive inhibition (allosteric)

another ligand binds to the allosteric site and changes the shape of the site or the enzyme which inhibits enzyme activity

What are the raw materials necessary to start photosynthesis?

6CO2 + 6H2O → C6H12O6 + 6O2

Carbon dioxide, water, and light energy.

Cellular respiration equation

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O

Role of oxygen in cellular respiration

Final electron acceptor in ETC and pulls spent electrons from chain, and combined w/ proteins = water → ATP

What does it mean to be phosphorylated?

A phosphate group has been added to a molecule, changing activity and function

Absorption spectrum/action spectrum

The range of wavelengths of light absorbed by a pigment; indicates which wavelengths are used in photosynthesis. The action spectrum illustrates the effectiveness of different wavelengths in promoting photosynthesis.

Fermentation, respiration and glycolysis

Total: 38 ATP

Fermentation: active Acid or alcoholic, yields 2 ATP

Respiration, oxidative phosphorylation: 32-34 ATP generated by oxidative phosphorylation, ATP synthase, Aerobic process, inner membrane of the mitochondria.

ETC: Cytochromes pass electrons, O2 final electron acceptor, makes water, H+ + O2 = H2O.

Krebs Cycle/Citric Acid Cycle: Anerobic process, pyruvate to acetyl CoA to citrate, produce and release CO2 as waste, 2 ATP generated by substrate level phosphorylation, electron carriers (NADH and FADH2) produced to prepare for ETC, anaerobic process, mitochondria matrix.

Glycolysis: 10 enzyme-driven reactions, splits= 2-3 molecules of pyruvate, uses 2 ATP by substrate level phosphorylation, made pyruvate and NADH, Anerobic process, in cytoplasm

Coenzymes

Organic, carriers for electrons and acetyl groups, facilitate biochemical reactions. Essential for ATP, biosynthesis and metabolic reactions.

Cofactors

Inorganic, stabilization, aid substrate binding, transfer electrons and groups, enable ATP transfer and oxygen transport

Signal transduction pathways

1. Ligan docks to G-Protein

2. 2. Alpha subunit docks to adenylyl cyclase

3. Adenylyl cyclase turns ATP to cAMP

4. cAMP docks to protein kinase

5. Catalytic parts get phosphorylated

6. Catalytic docks to phosphorylase, which docks to glycogen and releases glucose into the cell