Zoology 141 - Chemistry: pH Scale and Biological Macromolecules (Vocabulary Flashcards)

Vocabulary flashcards covering key terms from the pH scale, inorganic and organic biomolecules discussed in the lecture.

pH

A logarithmic scale measuring the hydrogen ion concentration of a solution; range 0–14 with 7 neutral.

Acid

A substance that donates hydrogen ions (H+) in solution.

Base

A substance that accepts hydrogen ions or releases hydroxide ions; basic.

Hydrogen ion

A proton; a positively charged ion that defines acidity.

Hydroxide ion

OH-; base-derived ion that neutralizes H+.

Neutralization

Acid-base reaction producing water and a salt.

Salt

Ionic compound that dissociates in water into cations and anions; electrolytes.

Electrolyte

Substance that conducts electric current in solution by dissociating into ions.

Strong acid

An acid that completely dissociates in water, releasing many H+.

Strong base

A base that completely dissociates in water, releasing OH-.

Weak acid

An acid that only partially dissociates in solution; can buffer.

Weak base

A base that only partially dissociates in solution; can buffer.

Buffer

Substance that resists pH changes by binding extra H+ or OH-.

Sodium bicarbonate

Weak base; buffering agent that neutralizes acids.

Dehydration synthesis

Bond-forming reaction joining monomers with loss of water; builds polymers; anabolic.

Hydrolysis

Bond-breaking reaction using water to split polymers; catabolic.

Monomer

A single building block that links to form polymers.

Polymer

Large molecule made of many monomers covalently bonded.

Carbohydrate

Biological macromolecule composed of carbon, hydrogen, and oxygen; energy storage and structure.

Monosaccharide

Simple sugar; building block of carbohydrates (e.g., glucose, fructose).

Disaccharide

Two monosaccharides linked by a covalent bond (e.g., sucrose, maltose, lactose).

Polysaccharide

Polymer of many monosaccharides (e.g., starch, glycogen, cellulose, chitin).

Glucose

A key monosaccharide; primary blood sugar used for energy.

Fructose

Monosaccharide isomer of glucose found in fruits; sweeter sugar.

Sucrose

Disaccharide of glucose and fructose; common table sugar.

Maltose

Disaccharide of two glucose units; product of starch digestion.

Lactose

Disaccharide in milk; glucose + galactose; digested by lactase.

Glycogen

Storage polysaccharide in liver and skeletal muscle; branched glucose polymer.

Cellulose

Structural polysaccharide in plant cell walls; rigid, not digestible by humans.

Chitin

Polysaccharide in exoskeletons of arthropods and some fungi.

Glycerol

Backbone molecule to which three fatty acids attach to form triglycerides.

Triglyceride

Neutral lipid with three fatty acid tails; main energy storage lipid.

Saturated fat

Fatty acid tails fully hydrogenated; straight chains; solid at room temperature.

Unsaturated fat

Fatty acid tails with double bonds; kinked; liquid at room temperature.

Phospholipid

Lipid with two fatty acid tails and a phosphate-containing head; amphipathic.

Phospholipid bilayer

Two-layer membrane with hydrophilic heads outward and hydrophobic tails inward; semipermeable.

Steroid

Lipid composed of four fused carbon rings; includes cholesterol and hormones.

Cholesterol

Steroid lipid; component of membranes and precursor to steroid hormones; excess linked to heart disease.

Lipitor

Statin drug that lowers cholesterol by inhibiting cholesterol synthesis.

Eicosanoids

Derivatives of arachidonic acid; include prostaglandins and leukotrienes; mediators of inflammation.

Prostaglandins

Eicosanoids involved in inflammation, pain, and other processes.

Leukotrienes

Eicosanoids involved in inflammation and immune responses.

Protein

Macromolecule made of amino acids; performs enzymes, structural roles, signaling, antibodies.

Amino acid

Organic molecule with amino group, carboxyl group, and variable R group.

Polypeptide

Chain of amino acids linked by peptide bonds; a protein may be a single or multiple polypeptides.

Primary structure

A protein’s linear sequence of amino acids.

Secondary structure

Folding patterns stabilized by hydrogen bonds; includes alpha helix and beta-pleated sheet.

Alpha helix

Right-handed helical secondary structure in proteins.

Beta-pleated sheet

Sheet-like secondary structure formed by hydrogen bonding.

Tertiary structure

Overall 3D shape of a single polypeptide; determined by side-chain interactions.

Enzyme

Protein catalyst that speeds up chemical reactions; examples include lactase.

Keratin

Structural protein in hair, nails, and skin; provides rigidity.

Collagen

Structural protein in connective tissues; provides strength and elasticity.

Hormone (protein)

Protein-based signaling molecule; examples include insulin.

Antibody

Protein used by the immune system to identify and neutralize foreign objects.

Nucleic acid

Biomolecule that stores and transmits genetic information; DNA and RNA.

Nucleotide

Monomer of nucleic acids; consists of a sugar, a phosphate, and a nitrogenous base.

DNA

Deoxyribonucleic acid; stores genetic information; usually double-stranded; bases A-T and C-G.

RNA

Ribonucleic acid; involved in protein synthesis; usually single-stranded; bases A-U and C-G.

ATP

Adenosine triphosphate; energy currency of the cell; released energy upon hydrolysis.

ADP

Adenosine diphosphate; product of ATP hydrolysis with release of phosphate.

Lactase

Enzyme that digests lactose into glucose and galactose.

Base pairing rules (DNA)

Adenine pairs with thymine; cytosine pairs with guanine.