Biology 1A Exam Review - Summer 2025

Vocabulary-style flashcards covering cell biology, metabolism, and photosynthesis concepts from the Biology 1A Summer 2025 exam transcript.

Thiols

Chemical compounds characterized by the functional group sulfhydryl ($-SH$).

Carboxyl group ($-COOH$)

A functional group that can donate a proton and function as an acid.

Carbonyl group ($C=O$)

A functional group that gives a carbon atom a partial positive charge, resulting in increased reactivity.

Desmosomes

Cell-to-cell junctions that are associated with intermediate filaments.

Tight junctions

Cell junctions that help to maintain the polarity of epithelial cells.

Microtubules

A class of cytoskeletal proteins that bind chromosomes during mitosis and form the ultrastructure of the flagellum in sperm cells.

Actin microfilaments

A class of cytoskeletal proteins that participate in muscle contraction.

Intermediate filaments

A class of cytoskeletal proteins that reinforce the nuclear envelope.

Redox potential of ionized P680

Must be more positive compared to the redox potential of oxygen/water to extract electrons from water.

Chl Ao

The primary electron acceptor for PS I (P700) which serves as a better electron donor compared to $NADP^+/NADPH$ due to its more negative redox value.

Average hydrogen bonds in liquid water

Liquid water usually has an average of $3.4$ hydrogen bonds with other water molecules.

Regulated exocytosis

A process exhibited only by cells specialized to secrete hormones or other extracellular products.

Hydrolase enzyme pathway

The path from synthesis to function is: rough ER $\rightarrow$ vesicle $\rightarrow$ Golgi complex $\rightarrow$ vesicle $\rightarrow$ lysosome.

Cytochrome b6f complex

A complex in the thylakoid membrane that is homologous to complex III in the inner membrane of the mitochondrion.

Lactate fermentation

A process in skeletal muscles that recycles $NAD^+$ from $NADH$. It does not release $CO_2$.

Crenulation

The shrinking of a red blood cell when placed in a hypertonic solution.

CAM plants

Plants that absorb $HCO_3^-$ only during nighttime hours and would be unable to minimize photorespiration under 24 hours of constant light.

Resonance energy transfer

The transfer of excitons occurring between antennae chlorophyll molecules and between antennae and the special pair of chlorophylls in the reaction center.

Pyruvate dehydrogenase enzyme complex

A complex that produces $NADH$, acetyl Co-A, and $CO_2$ as products of its catalytic activity.

Plastoquinone and Plastocyanin

Molecules that shuttle electrons between the photosystems in the thylakoid membrane.

Calvin Cycle turns for G3P

Three turns of the cycle are required to generate one molecule of glyceraldehyde-3-phosphate.

Equilibrium

The state of a reaction within a cell where the change in free energy ($\Delta G$) equals $0$.

Competitive inhibitor

An enzyme inhibitor that increases the $K_m$ of a reaction but does not cause an allosteric change and can be outcompeted by increasing substrate concentration.

Noncompetitive inhibitor

An enzyme inhibitor that decreases the $V_{max}$ by causing an allosteric change and cannot be outcompeted by the substrate.

Dynein

A molecular motor protein with ATPase activity that enables the motion of cilia and flagella.

Na+/K+ ATPase

An enzyme in the plasma membrane that transports three $Na^+$ ions out and two $K^+$ ions into the cell per cycle against their concentration gradients.

Theory of Endosymbiosis

The theory that mitochondria derived from ancient aerobic bacteria and that this event occurred before the endosymbiotic origin of chloroplasts.

Beta-oxidation

The metabolic pathway for degrading fatty acids; an 8-C fatty acid requires three cycles and produces four acetyl-CoAs.