Biology Lecture Notes - Vocabulary Practice Flashcards

Vocabulary flashcards covering key terms and concepts from the lecture notes (Pages 1–7).

Osmosis

Diffusion of water across a selectively permeable membrane from higher water potential to lower water potential.

Hypertonic solution

A solution with higher solute concentration outside the cell, causing water to move out and the cell to shrink.

Central vacuole

Large plant cell organelle that stores water and maintains turgor pressure; shrinkage indicates water loss.

Disulfide bond (S–S bond)

Covalent bond formed between sulfur atoms of cysteine residues, increasing protein stability.

Cysteine

Sulfur-containing amino acid capable of forming disulfide bonds.

Hydrogenation

Addition of hydrogen to unsaturated fatty acids, increasing saturation and often converting liquids to solids.

Bile salts

Amphipathic molecules that emulsify fats and act as surfactants, reducing surface tension.

Surface tension

Cohesive force at a liquid’s surface that makes it behave as if covered by a stretched film.

Transpiration

Loss of water vapor from plant surfaces, mainly leaves, driving water movement through the plant.

Water uptake (root uptake)

Absorption of water by plant roots from the soil to replace water lost by transpiration.

Directly correlated

A positive linear relationship between two variables; as one increases, the other increases.

Chlorophyll a

Pigment involved in photosynthesis; its concentration reflects nitrogen status and photosynthetic capacity.

Carbon

Element that forms the backbone of organic molecules; tetravalent and capable of diverse covalent bonding.

Electronegativity (carbon context)

A measure of an atom’s tendency to attract electrons; carbon’s electronegativity is moderate, not high, and C–H bonds are largely nonpolar.

Hydrogen bond

A weak interaction between a hydrogen atom bonded to a highly electronegative atom and another electronegative atom.

Lysosome pH

Lysosomes require acidic pH for enzyme activity; higher pH can inactivate enzymes.

Phosphorus

Essential element for ATP and other phosphate-containing molecules in energy metabolism.

ATP (adenosine triphosphate)

Cellular energy currency; energy stored in phosphate bonds and used for endergonic reactions.

CFTR mutation (phenylalanine deletion)

Deletion of phenylalanine affecting primary, secondary, and tertiary protein structure.

Rough endoplasmic reticulum

ER region studded with ribosomes where synthesis of secreted and membrane proteins occurs.

Simple diffusion

Passive movement of small nonpolar molecules down their concentration gradient without energy.

Lysosomal hydrolase

Enzymes in lysosomes that hydrolyze macromolecules, functioning best in acidic conditions.

Endosymbiotic theory

Mitochondria originated from engulfed prokaryotes; evidence includes own DNA and ribosomes.

Surface-area-to-volume (SA:V) ratio

A measure of how efficiently a shape can exchange substances with its surroundings; higher SA:V favors gas exchange.

Membrane protein folding anchor

Proper folding places hydrophobic regions in the membrane and hydrophilic regions outside, anchoring the protein.

Mitochondrion

Organelle that produces ATP via cellular respiration; contains its own DNA and ribosomes.

Endosymbiotic origin (mitochondria have own DNA/ribosomes)

Explanation that mitochondria evolved from engulfed prokaryotes and retained their own genetic systems.

Passive transport

Transport down a concentration gradient that requires no energy input.

Cholesterol in membranes

Sterol molecules embedded in the phospholipid bilayer that modulate fluidity and stability.

Cholinesterase

Enzyme that hydrolyzes acetylcholine by adding water, breaking covalent bonds.

Steroids

Lipid molecules derived from cholesterol (e.g., cholesterol, testosterone) with roles in structure and signaling.

Carrier protein

Protein that transports substances across membranes or through the bloodstream.

Glycogen

Branched polysaccharide used by animals for short-term energy storage; carbohydrate.

Branched carbohydrate

Carbohydrate with a branched structure (e.g., glycogen); characteristic of some polysaccharides.

H+ pump without ATP

Without ATP, proton pumps halt transport, stopping H+ movement across membranes.

Kidney microvilli

Microvilli increase surface area to volume for efficient exchange in renal tubules.

Organic compound feature (carbon–carbon bonds)

Carbon atoms covalently bonded to each other form the backbone of organic molecules.