Applied Algebra C957 WGU Module 2 Review questions and answers 2026

Enzymes

Proteins that allow biochemical processes to occur

Function of Enzymes

1. Increase reaction rates of biochemical reactions

2. Not consumed in the reaction

3. Help processes that would otherwise occur slowly

Advantages of Enzymes

1. Milder reaction conditions

2. Higher reaction rates within an organisms lifetime

3. Regulation (on/off when needed or not)

4. No side products

Transition State

Transient higher energy configuration that can decay to substrate or product

Cofactors

"helper molecules" Non protein chemical compounds or metallic ions required for some enzymes to become functional

Inorganic Ions

Cofactor- metals that binds electrostatic-ally or participate in redox reactions

Coenzymes

Cofactor- organic molecules that "move" chemical substituents

Prosthetic groups

Cofactor- coenzyme that are permanently attached to an enzyme

HoloEnzyme

ApoEnzyme (protein without cofactor) + Cofactor = HoloEnzyme

Equilibrium Constant

K'eq= [P] / [S]

Free Energy Change

If G is negative, the reaction proceeds spontaneously, without any energy input (by itself)

If G is positive, the reaction proceeds not spontaneously, with energy input.

Desolvation

Displacement of water molecules that would otherwise impeed the reaction.

What affects the activity of Enzymes?

1. Temperature

2. pH

3. Ionic Strength

4. Presence of cofactors and prosthethic groups

Acid base catalysis

Give and take protons

Covalent Catalysis

Covalent bond forming between the enzyme and substrate

Changes reaction pathway

Metal Ion Catalysis

Use redox cofactors, pKa shifters

Electrostatic catalysis

Preferential interactions with Ts

Kinetics

Study of the rate at which compounds react

Rate

Amount of product accumulated or substrate consumed per unit of time

Rate is affected by

-Temperature

-pH

-Ionic strength

-Substrate and enzyme concentration

Inhibitors

Compounds that decrease enzymes activity

Competitive inhibitors

Mimics substrate and competes for active site.

Do not affect catalytic function

Vmax unchanged and Km increased

Noncompetitive Inhibitor

Alters conformation of enzyme so active site is no longer fully functional; Inhibitor binds to another site on the enzyme.

Inhibits catalytic function

Vmax decreased and Km unchanged

Uncompetitive Inhibitor

Substrate can normally bind to active site

Increase substate binding; do not affect catalysis

Vmax and Km decreased

Mixed inhibitors (noncompetitive)

Bind to enzyme without bound substrate

Inhibit catalytic function and substrate binding

Carbohydrates

Sugars that come from Photosynthesis

Energy source and storage

Structural component of cell walls in plants and bacteria

Covalently linked with proteins

Monosaccharides

-Class of carbohydrate, simple sugars, one unit only

- Aldehydes or ketones with two or more hydroxyl groups

Hexose

Most common monosaccharide in nature

Enantiomers

Stereoisomers that are non-superimposable images of each other

Diastereomers

Sterioisomers that are NOT mirror images of each other

- Different physical properties

Epimers

Type of diastereomers

- Monosaccharides that differ only in the configuration around 1 carbon atom

Pyranoses

6 membered oxygen-containing rings

Furanoses

5 membered oxygen containing rings

Mutarotation

Formation of alpha or beta sugars

Disaccharides

Two monosaccharides joined together by an O-glycosidic bond

-Simplest Oligosaccharide

Glycosidic bond

Anomeric carbon of one monosaccharide reacting with carbon carrying hydroxyl group from the second monosaccharide.

Polysaccharides

Natural carbohydrates found as polymers

Polysaccharides can be

-homopolysaccharides: same units

-heteropolysaccharides: different alternating units

-linear

-branched

-storage and structural function

Starch

Main storage polysaccharide in plants

-mixture of two homopolysaccharides of glucose

Glycogen

Main storage polysaccharide in animals

-branched homopolysaccharide of glucose

Dextrans

Bacterial and yeast polysaccharides

-Branched homopolysaccharides of glucose

Cellulose

Fibrous, tough, water insoluble substance

- found in plant cell walls

Linear homopolymer of glucose

Cellulase

an enzyme which allows fungi, bacteria, and protozoa to use wood as a source of glucose.

Chitin

Principal component of the hard exoseleton of arthopods and cell walls of mushrooms

Agar

Complex mixture of heteropolysaccharide containing modified galactose. Used for growing bacteria

Agarose

Component of agar, gel separation

Glycosaminoglycans

Heteropolysaccharides of extracellular matrix in animals

- linear polymers of repeating diasaccharide units

Heparin

Linear polymer

Glycoproteins

Proteins with small oligosaccharides attachd

Glycolipids

Lipids with covalently attached oligosaccharide

Proteoglycans

Sulfated glucosaminglycans attached to a large rod-shaped proteins in cell membrane

Nucleotides

Building blocks of DNA

- Energy for metabolism (ATP)

-Enzyme cofactors (NAD+)

-Signal transduction (cAMP)

Nucleic Acids Functions

-Storage off genetic info

- Transmission of genetic information (mRNA)

-Processing of genetic information (ribozymes)

Nucleotide

-Nitrogenous base (Pyrimidines) (C, U or T)

- Pentose sugar (Ribose or Deoxyribose)

- Phosphate (Mono-, Di-, and Tri-phosphate)

Nucleoside

-Nitrogenous base (Pyrimidines) (C, U or T)

- Pentose sugar (Ribose or Deoxyribose)

Nucleobase

-Nitrogenous base (Pyrimidines) (C, U or T)

Cytosine

Pyrimdine: Both in DNA and RNA

Thymine

Pyrimdine: Only in DNA

Uracil

Pyrimdine: Found in RNA

Adenine and Guanine

Found in both RNA and DNA

Glycosidic bond

Pentose ring (sugar) is attached to the nucleobase

- Bond formed between anomeric carbon

Phosphodiester bond

Bonds link successive nucleotides in linear polymers

5' of one end --> 3' of the other sugar

DNA Backbone

Phosphates + Sugar = Backbone

Chargaff's Rule

A=T and C=G

Forms of DNA

- B form : predominant structure of DNA

- A form: dehydrated conditions for RNA

- Z form: GC rich

Central Dogma of Molecular Biology

DNA -> RNA -> Protein

- DNA and RNA are reversible

-Once DNA passed onto protein it CANT leave

mRNA

Carries genetic information from DNA to the ribosome where proteins are synthesized

tRNA

Adaptor molecules which bring amino acids to the ribosomes to carry out protein translation

rRNA (ribosomal RNA)

Main part of the ribosome which synthesize all proteins

Denaturation of DNA

-High temperature or change in pH

-Reversible: Annealing

Mutations

Alterations in DNA sequencing that produce permanent changes in the genetic information encoded

- related to aging and cancer

Lipids

Hydrophobic, organic molecules that are

- low solubility in water

-good solubility in nonpolar solvents

Functions of Lipids

- membrane structure in cellular membranes

- Storage of energy

-water repellant

-enzyme cofactors

-antioxidants

-pigments

-signalling molecules

Types of lipids

1. Non-fatty acid: cholesterol

2. Fatty acids:

- Storage lipids

- Membrane lipids

Fatty acids

Carboxylic acids with hydrocarbon chains containing between 4-36 carbons

- Saturated: no double bonds between carbons

- monounsaturated: one double bond between carbons

- polysaturated: more than one double bond

Triglycerols

Simplest lipids constructed from fatty acids

Advantage of fats over polysaccharides

- Fatty acids carry more energy

- Carry less water per gram

Trans fatty acids

Forms during parial hydrogenation of unsaturated fatty acids as an unwanted byproduct

Waxes

Esters of long chained saturated and unsaturated fatty acids with long chain alcohols

Structural Lipids in Membrane

Double layer of lipids that are amphipathic. One end is hydrophobic (inside) and one in hydrophilic.

-Polar head groups

- Nonpolar tails

Glycerophospholipids

Subtype of lipids

-Derivative of L-glycerol-3-phosphate

Sphingolipids

Subtype of lipids

-Backbone is made of amino alcohol sphingosine

Glycosphingolipids

Blood groups are determined by the type of sugars located on the head group of glycosphingolipids

Sterol: Cholesterol

Sterols: molecules that contain steroid nucleus

Cholesterol: Non fatty acid containing lipid

Functions of sterols

- modulate fluidity and permeability of membranes

-thicken the plasma membrane

-cholesterol bound to proteins, transported to tissues via blood vessels

- mammals obtain cholesterol from food or synthesize it in the liver

Steriod hormones

Steriods are oxidized derivatives of sterols

- More polar than cholesterol

Steriods are synthesized from cholesterol

Biological active lipids

play Active roles as signaling molecules between nearby cells

-Lipid soluble vitamins (A,D,E and K)

Biological Membranes

Cell membrane which separates interior parts of the cell from its surroundings

-composed of a variety of lipids and proteins

Functions of biomembranes

-Define cell boundaries

-Allow import and export of waste/nutrients

-retain metabolites and ions within the cell

-sense external signals and transmit information into the cell

-store energy as proton gradient

-support synthesis of ATP

Lipid Micelle

Form in the solution of amphipathic molecules that have larger head than tails

- Forms when the concentration of molecules is higher than a certain threshold

Lipid Bilayer

Forms in the solution of amphipathic molecules that have head and tail of equal cross section

Lipid Vesicles - liposomes

Small bilayers spontaneously seal into spherical vesicles

Flippases and Floppases

Enzymes that catalyze transverse diffusion of lipids from one leaflet to another

Fluid Mosaic Model

Structure of Biomembranes in Archaea

-Unique glycerol (D-glycerol-3-phosphate)

-Unique fatty acids (branched isoprene chains)

-Unique linages of fatty acids to glycerols (ether)

Functions of the proteins in the biomembrane

-Receptors: detecting signals from the outside (hormones)

- Channels, gates, pumps

-Enzymes (atp synthesis)

Three classes of membrane proteins

- Peripheral (Associate with the polar head group of membrane lipids)

-Integral (Span the entire membrane)

-Anchored (attached to membrane by fatty acid anchor)

Transporters (pumps)

-High specificity for particular substrates

- Behave like enzymes

-Gate at either membrane face

- move AGAINST a gradient

Ion Channels

-speficity for ion substrate

- single gate

-ions move DOWN a concentration gradient

Membrane transport systems