AP BIOLOGY FALL FINAL

Definition: The electron transport chain is a series of protein complexes and other molecules that transfer electrons from electron donors to electron acceptors via redox reactions. This process occurs in the inner mitochondrial membrane in eukaryotes.
Cellular Organelles with ETC:
- Mitochondria (in aerobic respiration)
- Chloroplasts (in photosynthesis)

Definition: Chemiosmosis involves the movement of ions across a selectively permeable membrane, down their electrochemical gradient, often coupled with ATP synthesis.
Cellular Organelles Performing Chemiosmosis:
- Mitochondria (during oxidative phosphorylation)
- Chloroplasts (during photophosphorylation)

Cyclins: Cyclins are proteins that regulate the cell cycle by activating cyclin-dependent kinases (CDKs).
Cyclin-CDK Complexes: These complexes control the progression of the cell cycle by phosphorylating target proteins, leading to advancement through the cell cycle phases.

Active Transport: Movement of ions against their concentration gradient, requiring energy (usually from ATP). E.g., Sodium-Potassium Pump.
Passive Transport: Movement of ions down their concentration gradient, not requiring energy. E.g., diffusion, osmosis.

Definition: ATP hydrolysis is the process by which ATP is broken down into ADP and inorganic phosphate, releasing energy that can be used for cellular work.

Storage and Release: ATP stores energy in the phosphate bonds, which can be released through hydrolysis, providing energy for various biological processes.
Common Energy Source: ATP is commonly used because it can release energy rapidly and efficiently for immediate cellular processes.

Dehydration Synthesis: A chemical reaction in which two molecules are bonded together with the removal of a water molecule, forming complex molecules like proteins or polysaccharides.
Hydrolysis: The chemical reaction involving the addition of water to break down molecules, such as polysaccharides into monosaccharides.

pH: The pH of a solution can indicate the rate of photosynthesis and cellular respiration based on the production of carbon dioxide and oxygen.
Formulas:
- Photosynthesis: $6CO2 + 6H2O ightarrow C6H{12}O6 + 6O2$
- Cellular Respiration: $C6H{12}O6 + 6O2 ightarrow 6CO2 + 6H2O + ATP$

Difference: Polar groups can form hydrogen bonds and are hydrophilic, while non-polar groups do not interact favorably with water and are hydrophobic.
Impact on Quaternary Structure: Polar groups facilitate interactions between subunits in proteins, while non-polar groups drive subunit folding and stabilization through hydrophobic interactions.

G0 Phase: Resting phase where cells exit the cycle and do not actively prepare to divide.
G1 Phase: Cell growth and metabolism, where the cell prepares for DNA synthesis.
S Phase: DNA replication occurs; each chromosome is replicated to form sister chromatids.
G2 Phase: Further growth and preparation for mitosis; DNA repair processes take place.
Prophase: Chromosomes condense, and the nuclear envelope begins to break down.
Metaphase: Chromosomes align at the cell's equator, and spindle fibers attach to centromeres.
Anaphase: Sister chromatids are pulled apart to opposite poles of the cell.
Telophase: Nuclear envelope re-forms around each set of chromosomes, which begin to decondense.
Cytokinesis: Final division of the cytoplasm, resulting in two separate daughter cells.

Positive Feedback: A process where the end product of an event enhances that event, e.g., action potentials in neurons.
Negative Feedback: A process where the end product of a reaction inhibits the pathway, maintaining homeostasis, e.g., insulin regulation of blood glucose levels.

Most Effective Method: Inhibitors that block receptor activity or downstream signaling cascades can effectively interrupt signal transduction pathways.

Definition: The endosymbiotic theory posits that mitochondria and chloroplasts originated as free-living prokaryotes that were engulfed by ancestral eukaryotic cells, leading to a symbiotic relationship.

Temperature Variation: Increased temperature can increase reaction rates up to an enzyme's optimal temperature, beyond which high temperatures can denature the enzyme, reducing activity.

Types:
1. G Protein-Coupled Receptors (GPCRs): Mediate various cellular responses through second messengers.
2. Receptor Tyrosine Kinases (RTKs): Involved in cell growth and differentiation.
3. Ion Channel Receptors: Allow ions to flow through membranes, triggering rapid cellular responses.
4. Intracellular Receptors: Respond to lipid-soluble signals that can cross membranes and alter gene expression.

Proton Gradient: A proton gradient affects the pH of the environment by creating an acidic or basic environment depending on the concentration of protons (H+ ions) present.

Krebs Cycle: Occurs in mitochondria; involved in aerobic respiration, generates NADH and FADH2 for the electron transport chain.
Calvin Cycle: Occurs in chloroplasts; involved in photosynthesis, uses ATP and NADPH to convert CO2 into glucose.

Saturated Fats: Fatty acids without double bonds, solid at room temperature, associated with increased cholesterol levels.
Unsaturated Fats: Contain one or more double bonds, liquid at room temperature, generally healthier and may lower cholesterol levels.

Nucleus: Contains genetic material (DNA) and controls cell activities through gene expression.
Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.
Cytoskeleton: Provides structural support, facilitates cell movement, and plays a role in intracellular transport.
Plasma Membrane: Semi-permeable barrier that regulates the entry and exit of substances, facilitating communication and signaling.

Oxygen: Essential for aerobic cellular respiration, acting as an electron acceptor leading to ATP production. In the absence of oxygen, cells undergo fermentation, producing less ATP and byproducts like lactic acid or alcohol.

Definition: The median value is the midpoint of a data set; it is the value separating the higher half from the lower half of the data set. To find it, the data must be arranged in order, and if there's an even number of observations, the median is the average of the two middle numbers.