JSU Cell Biology Exam 1

In what type of enzyme inhibition is a later product of a metabolic pathway inhibiting the activity of an earlier enzyme?

Feedback inhibition

The amino acids having R side chains with 1 or 2 methyl groups belong to the group of ________

non polar amino acid group

Which of the following biological molecules is a triose?

glycerol

Sucrose is a disaccharide composed of two simple sugars linked by what type of bond?

Glycosidic bond

In what type of enzyme inhibition does an inhibitor molecule bind to the enzyme-substrate to prevent the completion of the reaction?

Non-competitive inhibition

This biological molecule has a carboxyl head and a long hydrocarbon tail attached to it; which is it?

It is fatty acid

In what type of enzyme inhibition does an inhibitor molecule bind to the active site of an enzyme and prevent it from binding to its substrate?

Competitive inhibition

How many moles of glucose (C6H12O6, FW 180) are in 180g of glucose?

1

Most cellular proteins fold into final stable structures and remain that way; what is the term used to define that final stable structure?

Conformation

The function of which of the following biological molecules includes providing energy to the cell?

a. Sugars

b. Proteins

c. Lipids

d. All of the above

All of the above

Enzymes speed up biological reactions by doing which of the following?

a. lowering activation energy

b. changing the free energy of the reactants

c. both

d. neither

both

In what complex biological molecule(s) would you find an amino acid?

In a protein

Amino acids with positively charged R-side chains belong to the group of

basic amino acid group

The full 3-structure (α + β + random coiling + looping + foiling) of a protein that give the protein its final conformation is defined as its

tertiary structure

Which of the following is/are element(s) of a primary structure of a protein?

The sequence of its amino acids

What make the naturally occurring 20 amino acids found in living organisms different?

The R groups

How do cells make atoms and molecules react?

a. by changing their free energy

b. by changing their concentrations

c. by using enzymes

d. all of the above

e. none of the above

all of the above

Which pattern of protein folding is formed by H-bonds between NH and C=O groups in segments of the molecule oriented in the same direction?

Parallel β-sheet

Most cellular proteins fold into final stable structures and remain that way by different bonds; are ionic bonds part of these forces?

No

What are the proteins domains?

a. they are segments of proteins

b. they are independently folded segments of proteins

c. they are parts of proteins consisting of all other structures of a protein

d. all of the above

e. none of the above

all of the above

Name of the lipid molecule composed of a glycerol base to which are condensed 3 fatty acid?

triglyceride or glyceride

Name two non-covalent bonds with significance in the formation and stabilization of protein in a cell

H-bonds, electrostatic

What do chaperone proteins do to other proteins?

supervise and help

One thing common to steroid molecules like testosterone and cholesterol is that they all have what?

4-fused rings or hydroxyl group

What property of a phospholipid indicates that the molecule has a hydrophobic head and a hydrophilic tail at the same time?

amphipathic

Proteins are directional molecules, their two ends have names, what are they?

Carboxyl end, amino end

The tendency of things in the universe is to become disordered (entropy) but cells generate biological order; they do so by doing what?

Change in free energy or using enzymes

What is the nature of ΔG associated with spontaneous reactions?

negative

Give an example of an activated carrier molecule

ATP, NADPH, or NADPH2

What are two nonequivalent bonds that play major role in protein folding

hydrogen, ionic

What are two noncovalent bonds that play major role in protein folding

hydrogen, electrostatic

Besides being an enzyme list two functions of proteins

transport, shape, energy, chaperone

Give one function that is common to the 4 major biological molecules (sugars, lipids, proteins, nucleic acids)

use energy

In enzyme kinetics, what is the term used to define (enzyme-substrate)/time?

T.O.N. (turnover number)

Of Vmax and Km, which one is a characteristic of the enzyme?

Vmax

Define Km of an enzyme kinetic

concentration of a substance

Which of the following are purine based?

Guanine and Adenine

If the activity of the enzyme depends on a non-substrate that bind/or separate from it, the this type of regulation is called?

Allosteric regulation

A glycerol combined with three fatty acids is called?

Glyceride

Which amino acid combination would you expect to find more often near the center of a folded globular protein? Polar or non polar

Non polar sequence

Which amino acid combination would you more often find on the periphery of a folded globular protein?

polar sequence

There are 2 major types of bonds stabilizing a folded protein what are they?

hydrogen bonds and ionic bonds

The specific sequence of amino acids in a protein is defined as the protein's

primary structure

in α-helix structure of proteins, what type of chemical bond(s) is/are involved?

hydrogen bonds between functional groups

Amino acids with R-side chains carrying positive charges belong to what class?

Basic group

The active site of an enzyme binds____

By H-bond to the substrate

What causes prion disease such as Mad Cow Disease and CJD?

improper folding

How many molecules of glucose (C6H12O6 FW 180) are in 180g of glucose?

6.02 x 10^23

Which of the following are pyrimidine bases?

Thymine and Cytosine

Alanine, Valine and Leucine are amino acids whose R side chains have 1 to 2 methyl groups; these amino acids belong to which class?

non polar amino acids group

What type of covalent bond links glucose to fructose in sucrose?

Glycosidic bond

Proteins are structurally complex molecules formed by

polymerization of amino acids

What are domains of proteins

Unfolded segments of proteins

If a cell is in need of energy, it can use

a. sugars

b. proteins

c. lipids

d. all of the above

e. none of the above

all of the above

T/F The polypeptide backbone of proteins is branched

False

T/F the sequence of atoms in the polypeptide backbone varies from one protein to another

false

T/F Activated energy carriers provide metabolic energy cellular energy in the form of electrons and functional groups

True

Enzymes and catalysts of biological reactions; they do their jobs by _______ the activation energy of the reactions they catalyze

lowering

based on electrons involvement, metabolic relations can either be _______ or _______

oxidation; reduction

Ribose is _______ sugar while glycerol is a _______ sugar

Pentose; triose

Name two of the requirements for biological reactions

Temperature and atoms

Beside the sugar itself, in what biological molecule would you find a ribose?

RNA

How many tenets are in the cell theory?

3

Feedback inhibition

an earlier enzyme is inhibited by later product

Allosteric inhibition

causes enzymes to change conformation

competitive inhibition

when an inhibitor molecule binds to the active site of the enzyme

non competitive inhibition

when an inhibitor molecule binds to enzyme-substrate complex

phosphorylation

modification of protein

oxidation

loosing electrons, may also be gaining hydrogen ions (hydrogenation)

Reduction

gaining electrons, may also be losing hydrogen ions (deHydrogenation)

First law of thermodynamics

Energy can be converted from form to another but can not be created or destroyed

C4 plants

plants whose first product of the dark reaction is oxaloacetate (a 4-C compound)

essential amino acids

amino acids that cannot by synthesized by your body and therefore must be supplied in diet

peptides

small chain of amino acids

polypeptides

longer chain of amino acids or several peptides linked together

α-helix

regular structure that resembles a spiral staircase. protein folding pattern

β-sheet

protein folding pattern. form when segments of a polypeptide lie side by side and hydrogen bonds form between them

Primary structure

unique order of amino acids of a protein

secondary structure

formed by the proteins α-helix, coiled coils and its β-sheet (parallel, anti-parallel)

tertiary structure

the 3-D shape formed by α + β + random coiling + looping + folding

quaternary structure

peptide composition of the protein

domain

segments of a peptide that folded independently into a stable structure

Two types of metabolism

catabolism, anabolism

2nd law of thermodynamics

in the universe or any isolated system the degree of disorder (entropy) can only increase