Exam 2 Flashcards by Cassidy Dixon

An enzyme that temporarily undergoes covalent catalysis as part of its mechanism

Chymotrypsin

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The type of reaction catalyzed by proteases

Protein Breakdown

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The inhibitor which binds only to the ES complex and lowers the Vmax and Km

Uncompetitive

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The enzyme inhibition that can be overcome by increasing concentration of substrate

Competitive

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The shape of the kinetic plot of an enzyme that exhibits cooperative binding

Sigmodial

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An enzyme catalyst mechanism that uses anther molecule other than water to accept or donate a proton is what kind of catalytic strategy

General Acid-Base

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The sulfa drug, sulfanilamide, is what kind of inhibitor

Competitive

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What kind of inhibitor would you NOT have if you find out drug inhibition decreases when substrate concentration increased

Uncompetitive or Noncompetitive

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An uncompetitive inhibitor will have two_______ lines on a double reciprocal plot

Parallel

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Inhibitor which binds irreversible to the active site of an enzyme

Suicide

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Stabilizes the intermediate of the hydrolysis of a peptide bond to chymotrypsin

NH groups

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A ____________ inhibitor has a structure similar to the substrate and reversibly binds to the active site of the enzyme

Competitive

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Which three amino acids in chymotrypsin are found in the active site and play the most critical role in catalysis

Ser
His
Asp

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The mechanism of chymotrypsin involves the formation of an unstable _______-shaped intermediate that is stabilized by the oxyanion hole

Tetrahedral

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This is the organic portion of the heme group in hemoglobin

Protoporphyrin

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This type of hemoglobin is composed of two alpha chains and two y chains

Fetal

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This type of binding is indicated by a sigmoidal-shaped binding curve

Cooperative

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This condition is a result of a single point mutation in the beta chain of hemoglobin

Sickle cell anemia

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Under normal conditions, the heme iron in myoglobin and hemoglobin is in the_________ oxidation state

Ferrous

Fe2+

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The ability of myoglobin to bind oxygen depends on the presence of a bound prosthetic group called

Heme

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In hemoglobin, the iron of the heme is bonded to the four nitrogens of porphyrin and to the proximal_______ residue of the global chain

Histidine

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The binding of 2-3-bisphosphogycerate to hemoglobin___________ its affinity of oxygen binding

decreases

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The effects of pH on oxyge-binding of hemoglobin is referred to as the

Bohr effect

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Carbon dioxide reacts with the amino terminal groups of hemoglobin to form carbamate groups which carry a _______ charge

Negative

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The T-state of hemoglobin is stabilized by a salt bridge between beta1 Asp 94 and the C-terminal __________ of the beta1 chain

Histidine

In normal adult hemoglobin, HbA, the beta6 position is a glutamate residue, whereas in sickle cell hemoglobin, HbS, it is a ________ residue

Valine

As the pressure of carbon increases, the affinity of oxygen binding to hemoglobin ________

Decreases

2,3-Bisphosphoglcerate binds only to the ________ form of hemoglobin

Deoxy

This is the chemical form in which most of the carbon dioxide is transported in the blood

Bicarbonate | HCO3-

The HIV envelope is coated with what class of biomolecules

Carbohydrates

These monosaccharides differ at a single asymmetric carbon

Epimer

This is the most abundant organic molecule in the biosphere

Cellulose

The storage form of glucose in animals

Glycogen

The storage form of glucose in plants

Starch

These are the enzymes that synthesize oligosaccharides

Glycosyltransferases

These protein bind to specific carbohydrate structures

Lectins

In N-linked glycoproteins, the carbohydrate portion is attached to the residue in the protein

Asn

An O-linked glycoprotein is when the carbohydrate portion is attached to

Ser The Tyr (a.a. with -OH)

The influenza virus recognizes this acidic sugar molecule found on glycoproteins that are present on human cell surfaces

Sialic acid

What function group makes sialic acid acidic?

Carboxyl

Mostly, the pentasaccharide core of N-linked glycoproteins is made of

Mannose & N acetyl glucosamine

Proteoglycans

mostly sugar

Glycoprotein

mostly protein

A surface protein of influenza virus that binds to a sugar residue on the host cell membrane

Hemagglutinin

A surface protein of influenza virus that cleaves glycosidic bonds

Neuramindase

Carbohydrate component of RNA

D-ribose

Monosaccharide component of DNA

Deoxyribose

Sugar for DNA that is missing one -OH group

D-Deoxyribose

Most fatty acids have a ______ number of carbon atoms. Why?

Even | Biosynthesis requires C2

3 major types of membrane lipids

1. Phospholipids 2. Glycolipids 3. Cholesterol

Molecules that have both hydrophilic and hydrophobic moieties

amphipathic

What is common to proteins, nucleic acids, and polysaccharides that is not a feature of lipids?

Lipids don't form polymers | solubility

Lipids which contain carbohydrates

Glycolipid

Flat hydrophobic 4-ring molecule that is a precursor to many steroidal hormones

Sterol ring or cholesterol

Fat molecule that serves are the main energy storage in animals

Triacylglycerol

This membrane lipid composed of sphingosine, fatty acid, and a simple sugar

Cerebroside

Ionized fatty acids readily form ________ in aqueous solution

Micelles

Aqueous compartments enclosed by lipid bilayer

Liposomes

Three lipid molecules that can me attached to proteins to make the proteins associate with cell membranes

1. Palmitoyl Group 2. Farnesyl Group 3. GPI

Polycyclic hydrocarbon, often hydroxylated

Cholesterol

Phospholipids spontaneously form

Lipid bilayers

The driving force for the formation of membrane bilayers

Hydrophobic effect

Has a high permeability through lipid bilayers

Water

Protein only removed from a membrane with detergents

Intergral proteins

This substance inhibits prostaglandin H2 synthase-1 by blocking the channel through which the substance arachidonate travels

Aspirin

The type of amino acid found in the transmembrane helix of an integral protein

Non-polar

This is the process by which lipids and proteins move in the membrane bilayer

Lateral diffusion

These membrane components contain carbohydrates

Glycolipids

Bilayer lipid vesicle with an aqueous compartment

Liposomes

The effect of cholesterol on the phase-transition temp of cell membrane is to

Broaden Tm

Membrane proteins that are bound primarily by electrostatic and hydrogen bond interactions with the head groups of lipids

Peripheral

Some proteins ar anchored to the membrane by being covalently attached to a__________ by a thirster linkage to a specific cysteine residue

Palmitic group | Farynesal group

The temperature at which a phospholipid membrane transitions from a rigid to a fluid state is referred to as

An increase in the amount of unsaturated fatty acid chains in a membrane __________ the fluidity of the membrane

Increases