IB Bio HL: Enzymes

Enzyme

Huge proteins that can help breakdown, create, and edit. They are also biological catalysts that can spark or speed up a chemical reaction

Catalyze

To speed up a chemical reaction

Active site

The place where the substrate binds to

Substrate

The molecule the enzyme binds to (Ingredient/reactant to the factory-like enzyme)

Transition state

The high-energy, extremely unstable coupling of an enzyme/substrate that only exists for a split second and has the most energy relative to the rest of the reaction. (Peak of energy hill)

Activation energy

Energy needed to start a reaction

Denaturation

The process where too much heat or acid (pH) changes the shape and orientation of the enzyme permenantly. (Can no longer bind to substrate)

Immobile enzyme

Enzymes that stay in place; substrates come to them. Usually embedded in membranes. Ex: ATP Synthase

Dehydration Synthesis

Chemical reaction that joins molecules together by removing a water molecule. (Anabolic Rxns)

Intracellular

Enzymes work inside of the cell (can be mobile or immobile)

Concentration

The amount of substance/subcomponent present. Can be indicated through [ brackets ]. Ex: [S]

Competitve Inhibitor

Physically gets in the way of the substrate

Non-competitve Inhibitor

An inhibitor that bonds with an enzyme and changes its shape so the substrate no longer fits

Collision theory

For a chemical reaction to occur, the reacting particles must collide with one another.

Induced Fit

Enzyme causes (induced) the fit. As the substrate binds to the enzyme the enzyme molds around it. Also known as enzyme/substrate complex

Extracellular

Enzymes that work outside of the cell

Hydrolysis

A Chemical reaction where water breaks the bonds of a larger molecule and splits it to smaller parts

Mobile enzyme

enzymes that move around the cell. Have to catch the substrate to move to it. Pros: More collisions = more reactions. Cons: Costs energy to move and cell can’t control where rxn might happen. Ex: DNA Polymerase

Extracellular enzyme

Made by the cell then sent away. 1. Ribosomes make the enzyme, 2. Golgi body gives away protein tag, 3. Exocytosis (Get Out of my Cell!)

Ex: pepsin

Intracellular enzyme

Works inside the cell. Stays in the cell membrane (embeds) or Stays in the cytoplasm. Ex: cellular respiration or glycolysis.

Catabolism

Breaks molecules and releases energy

Anabolsim

Builds molecules and always require energy.

Metabolism

Sum of reactions in your body

Endothermic/Endergonic

Reaction when energy is gained. Takes from surroundings and feels COLD to the touch. Products have more energy than reactants

Exothermic/Exergonic

Reaction when energy is LOST! Puts it into the surrondings. Feels HOT to the touch. Products have less energy than the reactants