Biochemistry and Cell Biology Review

Vocabulary practice flashcards covering macromolecules, chemical indicators, enzyme catalysis, cell transport mechanisms, plant vs. animal cells, and mitochondrial structures.

Carbohydrates

Macromolecules whose main job is providing quick energy, composed of monosaccharide building blocks.

Benedict's solution

An indicator used to test for carbohydrates/simple sugars that begins blue and turns green, yellow, orange, or red when heated.

Starch

A macromolecule used for energy storage, composed of glucose molecules.

Iodine

An indicator solution used to test for starch that changes from yellow/brown to blue-black upon a positive result.

Proteins

Macromolecules responsible for growth, repair, and enzymes, composed of amino acid building blocks.

Biuret solution

An indicator used to test for proteins that starts blue and turns purple or violet upon a positive result.

Lipids

Macromolecules responsible for long-term energy, insulation, and cell membranes, composed of glycerol and fatty acids.

Sudan stain

An indicator used to test for lipids that produces a red/orange-stained lipid layer for a positive result.

Enzyme

A biological catalyst, usually made of protein, that speeds up a chemical reaction without being consumed by lowering activation energy.

Catalyst

A substance that speeds up a chemical reaction without being used up, accomplished by lowering the activation energy.

Substrate

The specific molecule that an enzyme acts upon in a chemical reaction.

Active site

The specific region of an enzyme where the substrate binds.

Enzyme-substrate complex

A temporary structure formed when a substrate is attached to the active site of an enzyme.

Product

What is produced by an enzymatic chemical reaction.

Activation energy

The energy needed to start a chemical reaction.

Denature

A process where an enzyme changes shape due to high temperature or extreme pH, altering the active site so the substrate no longer fits.

Optimal temperature

The temperature at which an enzyme functions best and exhibits its maximum reaction rate.

Optimal pH

The specific pH level where an enzyme works best; deviating too high or too low alters its shape and function.

Competitive inhibitor

A molecule that resembles the substrate and competes for the active site, preventing the substrate from binding.

Noncompetitive inhibitor

An inhibitor that binds at a site other than the active site, causing the enzyme's shape to change so the substrate cannot bind.

Simple diffusion

The passive movement of molecules from high to low concentration ($\text{high} \rightarrow \text{low}$) without requiring transport proteins or ATP energy.

Facilitated diffusion

The movement of substances from high to low concentration ($\text{high} \rightarrow \text{low}$) crossing the membrane with the help of transport proteins, without using ATP.

Channel proteins

Transport proteins that create an open passage through the membrane for specific molecules or ions to pass through.

Carrier proteins

Transport proteins that bind to a specific substance and change shape to move it across the membrane.

Active transport

The movement of substances from low to high concentration ($\text{low} \rightarrow \text{high}$) against the concentration gradient, requiring transport proteins/pumps and ATP energy.

Osmosis

The movement of water across a selectively permeable membrane toward the area with a higher solute concentration, requiring no ATP.

Hypertonic solution

An environment with a higher solute concentration outside the cell, causing water to move out of the cell, shriveling animal cells and shrinking plant cells away from the cell wall.

Hypotonic solution

An environment with a lower solute concentration outside the cell, causing water to enter the cell, which swells animal cells (potentially bursting them) and makes plant cells firm/turgid.

Isotonic solution

An environment with an equal solute concentration inside and outside the cell, resulting in no net movement of water and leaving cell size unchanged.

Cell wall

A rigid outer structure present in plant cells but absent in animal cells that provides extra support and helps prevent the cell from bursting when water enters.

Large central vacuole

A prominent, large organelle present in plant cells (compared to smaller vacuoles in animal cells) that stores water and supports cell rigidity.

Mitochondrion

An organelle present in both plant and animal cells that produces ATP through cellular respiration to provide usable energy for the cell.

Cristae

Folds of the mitochondrial inner membrane that increase surface area for cellular respiration.

Matrix (mitochondria)

The fluid-filled inner area of the mitochondrion containing enzymes needed for cellular respiration.