units 1-8 ap biology

How do cohesion and adhesion help plants?

They enable capillary action to pull water from roots to leaves.

Why does the R-group matter?

It determines the chemical properties and folding of a protein.

DNA vs RNA structure?

DNA is double-stranded (deoxyribose, T); RNA is single-stranded (ribose, U).

Polarity

Uneven charge distribution where Oxygen is negative (-) and Hydrogen is positive (+).

Hydrogen Bond

Weak attraction between polar molecules (e.g., between water molecules).

Cohesion

Water sticking to water.

Adhesion

Water sticking to other surfaces.

Surface Tension

Result of cohesion; allows things to float on water.

High Specific Heat

Water resists temperature changes.

Monomer

Small building block (e.g., amino acid).

Polymer

Large molecule of linked monomers (e.g., protein).

Dehydration Synthesis

Removing water to join monomers.

Hydrolysis

Adding water to break polymers apart.

Carbohydrate

Energy and structure; composed of Carbon, Hydrogen, and Oxygen (C, H, O).

Lipid

Hydrophobic; energy storage and membranes; composed of Carbon, Hydrogen, Oxygen, and Phosphorus (C, H, O, P).

Protein

Polymers of amino acids; composed of Carbon, Hydrogen, Oxygen, Nitrogen, and Sulfur (C, H, O, N, S).

Nucleic Acid

Genetic information (DNA/RNA); composed of Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus (C, H, O, N, P).

Protein Mutation

If a hydrophilic amino acid is swapped for a hydrophobic one, the protein will fold differently, likely losing function.

Denaturation

High heat or pH changes break hydrogen bonds, changing protein shape and stopping function.

Evaporative Cooling

High heat of vaporization allows sweat to remove body heat efficiently.

α (Alpha) Linkages

Curved/helical chains found in starch and glycogen; easily broken down by enzymes.

β (Beta) Linkages

Straight rigid fibers found in cellulose; humans cannot digest.

Ribosome

Site of protein synthesis.

Endoplasmic Reticulum (ER)

Rough (proteins) and Smooth (lipids/detox).

Golgi Complex

Folding, chemical modification, and packaging of proteins.

Mitochondria

Site of ATP production (double membrane).

Lysosome

Contains hydrolytic enzymes for digestion/recycling.

Vacuole

Storage (water/waste); large central vacuole in plants.

Chloroplast

Site of photosynthesis (algae/plants).

Surface Area-to-Volume Ratio

Smaller cells are more efficient at exchange.

Phospholipid Bilayer

Amphipathic membrane (hydrophilic heads, hydrophobic tails).

Selective Permeability

Ability of membrane to regulate what enters/exits.

Facilitated Diffusion

Passive transport via membrane proteins.

Active Transport

Requires ATP to move molecules against gradient.

Endocytosis/Exocytosis

Bulk transport into/out of cell.

Tonicity

Ability of solution to cause a cell to gain/lose water (Hyper, Hypo, Iso).

SA:V Ratio Effect on Cell Size

As a cell grows, volume increases faster than surface area, making it harder to move materials in/out.

Organelle Interaction

Describing how a protein moves from a Ribosome -> ER -> Golgi -> Plasma Membrane.

Water Potential Movement

Water moves from areas of High Water Potential (low solute) to Low Water Potential (high solute).

Membrane Evolution

The Endosymbiotic Theory (Mitochondria/Chloroplasts having their own DNA and double membranes).

Turgor Pressure

Internal pressure against the cell wall caused by water entering a plant cell.

Aquaporins

Specialized protein channels that facilitate the rapid transport of water, move with concert graduation and until equilibrium

Ion Channels

Proteins that allow specific ions to pass through the membrane down their gradient.

Hypertonic

Higher solute concentration outside; causes cell to lose water.

Hypotonic

Lower solute concentration outside; causes cell to gain water.

Turgor Pressure Role

It provides structural support to plants by keeping cells rigid in hypotonic environments.

Aquaporins Necessity

While water can slowly diffuse across the membrane, aquaporins allow for the massive, rapid flow of water needed for osmoregulation.

Osmosis

The net diffusion of water across a selectively permeable membrane.

Hypotonic Solution Effect

Water moves IN; animal cells may burst (lyse); plant cells become turgid (ideal).

Hypertonic Solution Effect

Water moves OUT; animal cells shrivel; plant cells undergo plasmolysis.

Isotonic Solution Effect

Equal solute; no net water movement; animal cells are stable; plant cells become flaccid.

Water Hydrogen Bonds Property

Water is polar, allowing hydrogen bonding between molecules.

Water as a Good Solvent for Polar Molecules

Its polarity allows it to surround and interact with other polar molecules, dissolving them.

Carbohydrate Structure and Function Relation

Monosaccharides are energy sources; polysaccharides like starch store energy, and cellulose provides structural support in cell walls.

Saturated vs Unsaturated Fats

Saturated fats have no double bonds, are solid at room temp; unsaturated fats have double bonds, are liquid at room temp.

Phospholipid Function in Cell Membrane

They form a bilayer with hydrophilic heads facing out and hydrophobic tails inside, providing a selective barrier.

Enzyme Role in Chemical Reactions

They lower activation energy and stabilize the transition state.

Temperature and pH on Enzyme Activity

Extreme temperatures or pH can denature enzymes, reducing or stopping activity.

ATP Energy Storage and Release

Energy is stored in the phosphate bonds; breaking the terminal phosphate bond releases energy for cellular processes.

Prokaryotic vs Eukaryotic Cells

Prokaryotes lack a nucleus and membrane-bound organelles; eukaryotes have both.

Free vs Bound Ribosomes in Eukaryotic Cells

Free ribosomes make proteins for use in the cytosol; bound ribosomes make proteins for export or membranes.

Maintaining Homeostasis in Water Balance

Through osmosis; water moves from high to low concentration across semi-permeable membranes.

Fluid Mosaic Model Explanation

The cell membrane is a dynamic structure with proteins embedded in a phospholipid bilayer that allows movement and flexibility.

Dehydration Synthesis vs Hydrolysis

Dehydration synthesis builds polymers by removing water; hydrolysis breaks polymers by adding water.

Enzyme Specificity to Substrates

The active site has a shape complementary to the substrate (lock-and-key or induced fit model).

Functional Groups Effect on Macromolecule Properties

They determine polarity, solubility, and chemical reactivity, influencing biological function.

DNA vs RNA Structure and Function

DNA is double-stranded, stores genetic info; RNA is single-stranded, involved in protein synthesis.

Cells Using Energy from Chemical Reactions

They couple exergonic reactions (release energy) to endergonic reactions (require energy), often using ATP.

Enzymes Role in Metabolic Pathways

They control the rate of each step, ensuring efficient energy use and product formation.

Water Cohesion and Adhesion Importance for Plants

Cohesion helps water move through xylem; adhesion allows water to stick to cell walls, aiding transport.

Temperature and Solvent Effects on Chemical Reactions

Higher temperatures increase reaction rates; solvents can stabilize or destabilize reactants and products.

Enzyme

A biological catalyst (usually a protein) that speeds up reactions by lowering activation energy.

Substrate

The specific reactant an enzyme acts on.

Active Site

The region of the enzyme where the substrate binds.

Denaturation

When an enzyme loses its shape (and function) due to high heat or extreme pH.

Activation Energy ($E_a$)

The initial energy required to start a chemical reaction.

Competitive Inhibitor

A molecule that binds to the active site, blocking the substrate.

Noncompetitive (Allosteric) Inhibitor

A molecule that binds to a different site, changing the enzyme's shape so the substrate can't fit.

First Law of Thermodynamics

Energy cannot be created or destroyed, only transformed.

Second Law of Thermodynamics

Every energy transfer increases the entropy (disorder) of the universe.

Photosynthesis

The process of capturing light energy to make organic compounds (glucose).

Cellular Respiration

The process of breaking down glucose to produce ATP.

ATP (Adenosine Triphosphate)

The main energy currency of the cell.

Light-Dependent Reactions

Occur in the thylakoid. Use light and water to produce NADPH, ATP, and $O_2$ (waste).

Calvin Cycle (Light-Independent)

Occurs in the stroma. Uses ATP, NADPH, and $CO_2$ to produce G3P (sugar).

Glycolysis

Occurs in the cytosol. Breaks glucose into pyruvate (produces 2 ATP, 2 NADH).

Krebs Cycle (Citric Acid Cycle)

Occurs in the mitochondrial matrix. Produces $CO2$, ATP, NADH, and $FADH2$.

Oxidative Phosphorylation

Occurs on the inner mitochondrial membrane (ETC). Uses $O2$ and electrons from NADH/$FADH2$ to make ~30-34 ATP.

Temperature Effect on Enzyme Activity

Activity increases with temp up to an optimal point, then drops sharply as the enzyme denatures.

Final Electron Acceptor in ETC

Oxygen (it combines with $H^+$ to form water).

No Oxygen Consequence

The cell undergoes Fermentation (Lactic Acid or Alcoholic) to recycle NAD+ so glycolysis can continue.

Mitochondria Structure

Outer Membrane (smooth), Inner Membrane (Cristae), Matrix (Krebs Cycle), Intermembrane Space (H+ ion gradient).

Chloroplast Structure

Thylakoids (site of Light Reactions), Stroma (Calvin Cycle), Chlorophyll (main pigment, absorbs light).

Calvin Cycle Process

1. Carbon Fixation (CO2 + RuBP via Rubisco). 2. Reduction (ATP, NADPH -> G3P). 3. Regeneration (recycles G3P to RuBP).

Fermentation Goal

To recycle NAD+ so that Glycolysis can keep running and making a small amount of ATP.

Lactic Acid Fermentation

Occurs in muscle cells; produces lactate.

Alcoholic Fermentation

Occurs in yeast; produces Ethanol and CO2.

Carotenoids

Yellow/orange/red pigments that absorb extra light energy to protect chlorophyll from damage.

Rubisco

The enzyme that 'fixes' inorganic carbon into the Calvin Cycle.

RuBP

The 5-carbon molecule that starts the Calvin Cycle.