IB Bio Proteins & Enzymes

These flashcards cover key vocabulary related to proteins, their structures, and functions as discussed in the lecture notes.

Proteins

Large, complex molecules made up of amino acids that perform a variety of functions in living organisms.

Amino Acids

The building blocks of proteins, consisting of a central carbon, amino group, carboxyl group, and variable R group.

Polypeptide

A polymer of amino acids joined together by peptide bonds.

Peptide Bond

Covalent bond formed between the amine group of one amino acid and the carboxyl group of another.

Primary Structure

The unique sequence of amino acids in a polypeptide chain.

Secondary Structure

Local folding of the polypeptide chain into alpha helices and beta pleated sheets.

Tertiary Structure

The overall three-dimensional shape of a polypeptide, determined by interactions between R groups.

Quaternary Structure

The structure formed when two or more polypeptide chains bond together.

Denaturation

A process in which a protein loses its native conformation, becoming biologically inactive.

Enzymes

Globular proteins that act as biological catalysts to speed up chemical reactions.

Substrate

The specific reactant that an enzyme acts upon.

Active Site

The region on the surface of an enzyme where substrates bind and reactions are catalyzed.

Genetic Code

The sequence of DNA or RNA that determines the sequence of amino acids in a protein.

Rubisco

An enzyme that catalyzes the first step of carbon fixation in photosynthesis.

Hemoglobin

A protein in red blood cells that carries oxygen from the lungs to the body.

Insulin

A hormone produced by the pancreas that regulates glucose levels in the blood.

Immunoglobulins

Antibodies produced by the immune system to identify and help remove foreign objects.

Rhodopsin

A light-sensitive pigment found in the photoreceptor cells of the retina.

Collagen

A structural protein that provides strength and support in connective tissues.

Spider Silk

A protein that exhibits exceptional tensile strength and elasticity, produced by spiders.

Covalent Bonds

Strong chemical bonds formed by the sharing of electrons between atoms.

Hydrogen Bonds

Weak attractions between polar molecules that are important for protein structure.

Disulfide Bridges

Covalent bonds formed between the sulfur atoms of cysteine residues, stabilizing protein structure.

Hydrophobic Interactions

Forces that drive nonpolar amino acid side chains away from water, influencing protein folding.

Ionic Bonds

Attractions between positively and negatively charged side chains of amino acids.

Metabolic Pathway

A series of chemical reactions in a cell that are catalyzed by enzymes.

Competitive Inhibition

A type of enzyme inhibition where an inhibitor competes with the substrate for the active site.

Non-competitive Inhibition

An inhibitor binds to an enzyme at a site other than the active site, altering enzyme function.

Feedback Inhibition

A regulatory mechanism where the end product of a metabolic pathway inhibits an earlier enzyme.

Proteome

The complete set of proteins expressed by a specific organism or cell at a given time.

Genome

The complete set of genes or genetic material present in a cell or organism.

Lactase

An enzyme that breaks down lactose into glucose and galactose.

Lactose Intolerance

A condition where the body does not produce enough lactase, leading to digestive discomfort.

Dehydration Synthesis

A chemical reaction that forms a bond between two molecules and produces water as a byproduct.

Hydrolysis

The reaction that breaks down a compound by adding water.

Essential Amino Acids

Amino acids that must be obtained from the diet because the body cannot synthesize them.

Zwitterion

A molecule that bears both positive and negative charges, commonly found in amino acids.

Polarity of Amino Acids

The characteristics of amino acids that affect their interactions and solubility.

Hydrophobic Amino Acids

Amino acids with nonpolar side chains that avoid water.

Hydrophilic Amino Acids

Amino acids with polar or charged side chains that interact favorably with water.

R Group

The variable side chain of an amino acid that determines its characteristic and chemical properties.

Carbon Fixation

The process of converting inorganic carbon (CO2) into organic compounds by living organisms.

Biotechnology

The use of living systems and organisms to develop or make useful products.

Gel Electrophoresis

A method used to separate proteins or nucleic acids based on size and charge.

Amino Acid Sequence

The order of amino acids in a polypeptide chain, which determines the protein's structure and function.

Condensation Reaction

A chemical reaction that involves the joining of two molecules with the loss of a small molecule, often water.

Translation

The process by which ribosomes synthesize proteins using mRNA as a template.

X-Ray Crystallography

A technique used to determine the three-dimensional structure of proteins.

Enzyme Kinetics

The study of how enzymes bind to substrates and turn them into products.

Lock and Key Model

A model of enzyme action that explains how substrates fit into the active site of enzymes.

Induced Fit Model

A model of enzyme action that describes how enzymes change shape to fit substrates.