BIOL 1101 Biological Molecules, Energy, Enzymes, and Cellular Respiration Vocabulary

Vocabulary flashcards covering biological molecules, energetics, enzymes, and cellular respiration based on the exam study guide.

Carbohydrates (Building Blocks)

Monosaccharides and disaccharides.

Lipids (Building Blocks)

Fatty acids.

Proteins (Building Blocks)

Amino acids.

Nucleic Acids (Building Blocks)

Nucleotides.

Covalent Bond

A chemical bond formed when two atoms share electrons.

Polar Covalent Bond

A covalent bond in which electrons are shared unequally between atoms due to differences in electronegativity.

Nonpolar Covalent Bond

A covalent bond in which electrons are shared equally between atoms.

Ionic

An attraction between oppositely charged ions resulting from the complete transfer of electrons.

Hydrogen Bond

A weak attraction between partial positive charges (such as on hydrogen) and partial negative charges on nearby polar molecules.

Hydrophilic

Water-loving; describes polar or charged molecules that readily interact with and dissolve in water.

Hydrophobic

Water-fearing; describes nonpolar molecules that do not dissolve in water.

Cohesion

The property of water molecules sticking to one another through hydrogen bonding.

pH

A measure of the hydrogen ion ($H^+$) concentration in a solution, indicating its relative acidity or alkalinity.

Buffer

A substance or solution that resists drastic changes in pH by accepting or donating hydrogen ions.

Dehydration

A chemical reaction that combines biological monomers into polymers by removing a molecule of water.

Hydrolysis

A chemical reaction that breaks polymers down into building blocks using a molecule of water ($H_2O$).

Kinetic Energy

The energy of motion, such as water moving across a biological membrane.

Potential Energy

Stored energy available to do work, such as chemical potential energy stored in glucose.

ATP

Adenosine triphosphate; acts as the cell's rechargeable battery, providing instant usable energy in precise amounts for cellular processes.

Catabolic Reactions

Metabolic pathways that break down larger molecules into smaller ones, releasing usable energy.

Anabolic Reactions

Metabolic pathways that build larger molecules from smaller building blocks, requiring an input of energy.

Metabolic Coupling

The pairing of energy-releasing (exergonic) reactions with energy-requiring (endergonic) reactions to drive reactions that would not proceed on their own.

ATP Hydrolysis

The exergonic reaction using $H_2O$ to break phosphate groups ($PO_4^{3-}$) off ATP, releasing energy for cellular work.

Enzyme

A biological protein catalyst that speeds up chemical reactions by lowering the activation energy without being consumed.

Active Site

The specific region on an enzyme where substrate molecules bind and undergo catalysis.

Enzyme Saturation

The state reached when all active sites of an enzyme are occupied by substrate, causing the reaction rate to level off.

Competitive Inhibition

Inhibition occurring when an inhibitor directly competes with the substrate for binding at the enzyme's active site.

Noncompetitive Inhibition

Inhibition occurring when an inhibitor binds to a site other than the active site, altering the enzyme's shape and reducing activity.

Denaturation

The loss of a protein's functional 3D shape due to high temperature or extreme pH disrupting non-covalent chemical interactions.

Cellular Respiration Equation

$$\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{ATP}$$

Glycolysis

An anaerobic process occurring in the cytoplasm that breaks 1 glucose molecule into 2 pyruvate molecules, producing ATP and NADH.

Pyruvate Oxidation

The transition step where pyruvate enters the mitochondrion, loses 1 carbon as $\text{CO}_2$ gas, and forms Acetyl-CoA.

Citric Acid Cycle

A pathway in the mitochondrial matrix that oxidizes remaining carbon to $\text{CO}_2$, producing $\text{FADH}_2$, NADH, and ATP.

NAD+

An electron carrier that accepts 2 high-energy electrons and a proton to become reduced NADH, bridging glycolysis and the citric acid cycle to the electron transport chain.

Electron Transport Chain (ETC)

A series of protein complexes in the inner mitochondrial membrane that use electron energy from NADH and $\text{FADH}_2$ to pump $\text{H}^+$ ions into the intermembrane space.

Proton Gradient

An electrochemical gradient created by pumping $\text{H}^+$ out of the matrix into the intermembrane space, storing potential energy for ATP synthesis.

ATP Synthase

An enzyme complex in the inner mitochondrial membrane powered by $\text{H}^+$ flow back into the matrix to synthesize ATP from ADP and inorganic phosphate.

Oxygen (in Respiration)

The final electron acceptor in the electron transport chain that combines with electrons and protons to form $\text{H}_2\text{O}$, keeping the chain running and regenerating $\text{NAD}^+$.

Upstream Accumulation

The metabolic outcome where blocking a specific enzyme causes reactant molecules directly preceding the block to accumulate.

Downstream Depletion

The metabolic outcome where blocking a specific enzyme causes product molecules following the block to disappear because new molecules are not produced.