Bio Enzyme Quiz

proteins

molecule made up of amino acids

amino acids

molecules that combine to form proteins

nucleotides

the basic building block of nucleic acids (RNA and DNA)

peptide bonds

a covalent bond that links amino acids together to form a protein

polypeptides

A substance that contains many amino acids (the molecules that join together to form proteins).

denaturation of protein

process modifying the molecular structure of a protein.

enzymes

organic catalyst (proteins encoded by genes)

functional groups in proteins

amino, hydrogen, carboxyl, and R group

list 3 different proteins, and their functions. 

Contractile proteins - Proteins that allow for contraction, like actin and myosin.

Enzymes - Proteins that speed up chemical reactions, like lactase.

Hormonal proteins - Proteins that carry chemical messages through the body, like insulin.

What are enzymes, and why are they so important to Biology?

Enzymes are proteins, they act as catalysts, which means that they make biochemical reactions happen faster than they would otherwise.

Why are enzymes classified as catalysts?

they increase the rate of chemical reactions without themselves being consumed or permanently altered by the reaction.

what do the various enzyme graphs look like? (reaction rate vs. pH, Temp., substrate concentration, or enzyme concentration)

substrates need to be in excess for line and curve is for limited substrates

substrate

reactants of an organism+breaks things down

induced fit

hugs substrate to fit (changes shape in enzyme)

active site

where substrates undergo a chemical reaction

activation energy

The initial energy needed to start a chemical reaction is called the free energy of activation

enzyme-substrate complex

a temporary molecule formed when the substrate binds to the enzyme

cofactors

non protein enzyme helpers

coenzyme

An organic cofactor (includes vitamins)

competitive inhibitors

bind to the active site of an enzyme, competing with the substrate

non competitive inhibitors

bind to another part of an enzyme, causing the enzyme to change shape and making the active site less effective

allosteric regulation

any form of regulation where the regulatory molecule (an activator or inhibitor) binds to an enzyme someplace other than the active site.

activator

a molecule that increases the activity of an enzyme or a protein that increases the production of a gene product in DNA transcription.

inhibitor

chemical or biological molecules that regulate chemical reactions by slowing down or blocking them from occurring.

Free Energy (ΔG)

a measure of energy that is available to do work.

Compare and pH, Temperature, Substrate, and Enzyme reaction graphs.

pH is curve up slope down, temprature is straight line up curve down, substrate is slope up and straight ascent,

Compare and contrast competitive vs. non-competitive (allosteric) enzyme inhibition. 

Allosteric involves binding to a site other than the active site, competitive is direct competition at active site.

Is delta G affected by enzyme and does it change?

Delta G never changes and is never affected by enzyme.

non competitive enzyme

allosteric

ANY molecule that helps speed up a chemical reaction is called?

catalyst

What do enzymes do to the activation energy of a reaction?

Decrease the amount

How do enzymes affect the rate of a chemical reaction?

Increase the rate

What is the biological molecule called that the enzyme acts on?

substrate

When an enzyme is catalyzed and the substrate is broken down, what is formed?

products

In a rate of reaction graph, why might the graph level off as you add substrates?

limited amount of enzymes

What type of inhibition stops enzyme activity by having the same shape and directly attaching to the active site? 

competitive

How does an enzyme increase the rate of reaction?

by lowering activation energy

The substance that goes into the active site is called

substrate

The intermediate step in the enzymatic process is called

enzymes substrate complex

Can an enzyme work with any substrate?

no

The process where by a substance is broken down is called

catabolic

The process where by a substance is built up is called

anabolic

Do all enzymes work at the same pH?

no (ph)

catalyst

chemical agent that speeds up a reaction without being consumed by the reaction

Activation energy is often supplied in the form of ___ energy that the reactant molecules ___ from their surroundings

thermal, absorb

enzymes ___ energy that would have happened already

quicken

The active site can lower an E_A barrier by

orienting substrates correctly

straining substrate bonds

provided a favorable microenvironment

are cofactors organic?

yes and no (could be both)

what do mutations lead to?

changes in amino acid composition of an enzyme

how do altered amino acids alter a substrate

specifically