Biochem Section 2

Front 1

If a chemical system in equilibrium is disturbed, the system will adjust to restore equilibrium.

Back 1

Le Chatelier's Principle

Front 2

The measure of a solutions acidity. It is the negative log of the hydrogen ion concentration.

Back 2

pH

Front 3

What is the Henderson-Hasselbach equation?

Back 3

pH= pKa + log( [conjugate base]/[acid])

Front 4

A solution that has the ability to resist changes in pH upon the addition of small amounts of either acid or base. Composed of a weak acid or base and salts of its conjugate acid/base

Back 4

Buffers

Front 5

Homeostatic range for blood pH

Back 5

7.35-7.45

Front 6

What is the pH for blood acidosis

Back 6

<7.35

Front 7

What is the pH for blood Alkalosis

Back 7

>7.45

Front 8

What are the three homeostatic regulators of H+?

Back 8

Chemical buffer system, respiratory mechanism, and renal mechanism

Front 9

Buffer system that is important in tubular fluids of kidneys, as well as in buffering ICF

Back 9

Phosphate Buffer System

Front 10

Buffer system that is the most significant buffering compound in blood. Important in buffering ECF

Back 10

Carbonic acid- bicarbonate buffer system

Front 11

Three types of protein buffers

Back 11

1) Plasma protein buffers; 2) amino acid buffers; 3) hemoglobin buffers

Front 12

Condition in which blood pH drops due to decrease in CO2 exhaled and increase in CO2 retained. Can be due to hypoventilation, apnea, emphysema, etc.

Back 12

Respiratory Acidosis

Front 13

Increase in blood pH due to increase of CO2 exhaled. Can be due to things such as hyperventilation, high altitudes, stress, anxiety, etc.

Back 13

Respiratory Alkalosis

Front 14

Drop in blood pH due to a loss of bicarbonate or an overabundance of acid in the blood. Can be due to things such as alcoholism, diabetes, aspirin intake, chronic diarrhea, etc.

Back 14

Metabolic Acidosis

Front 15

Type of hyperventilation used to bring up pH when suffering from metabolic acidosis

Back 15

Kussmaul breathing

Front 16

Rare rise in blood pH generally caused from overabundance of bicarbonate or loss of acid from the blood. Can be from overuse of antacids, chronic vomiting, loss of stomach acid, diuretic overuse, etc.

Back 16

Metabolic alkalosis

Front 17

an active enzyme with its nonprotein component

Back 17

Holoenzyme

Front 18

Enzyme without its nonprotein moiety. Inactive

Back 18

Apoenzyme

Front 19

nonprotein moiety that is a metal ion

Back 19

Cofactor

Front 20

nonprotein moiety that is a small organic molecule

Back 20

Coenzyme

Front 21

Coenzymes that only transiently associate with an enzyme

Back 21

Cosubstrate

Front 22

Pocket or groove on the surface of the protein into which the substrate fits

Back 22

Active site

Front 23

Enzyme's tertiary structure consists of a unique pocket or site which is tailor-made to fit only its substrate

Back 23

Lock and Key model

Front 24

As enzymes interact with substrates, change their conformation such that the enzyme is snug around the substrate

Back 24

Induced-fit model

Front 25

Factors affecting Reaction rates

Back 25

Temp and pH; Enzyme concentration; Substrate concentration

Front 26

When the active sites on all enzymes are engaged

Back 26

Enzyme saturation

Front 27

Michaelis-Menten Equation

Back 27

V= Vmax[S]/ ([S]+Km)

Front 28

The affinity of the enzyme for the substrate. Low= high affinity and tight binding; High= low affinity and weak binding

Back 28

Km

Front 29

Any substance that can diminish the velocity of an enzyme-catalyzed reaction

Back 29

Inhibitor

Front 30

Inhibitors that bind to enzymes through covalent bonds

Back 30

Irreversible inhibitors

Front 31

Inhibitors that bind to enzymes through noncovalent bonds

Back 31

reversible inhibitors

Front 32

Inhibitor that binds reversibly to the same site as the substrate. It increases Km for a given substance, requiring more substrate to reach Vm. Ex: Statins

Back 32

Competitive Inhibition

Front 33

When an inhibitor and substrate bind to different sites on an enzyme

Back 33

Noncompetitive inhibition

Front 34

Allosteric effectors that inhibit enzyme activity (takes more substrate to get to 1/2 Vmax)

Back 34

Negative effector

Front 35

Allosteric effector that increases enzyme activity (takes less substrate to get to 1/2 Vmax)

Back 35

Positive effectors

Front 36

Enzymes that have multiple subunits and are regulated by effectors

Back 36

Allosteric enzymes

Front 37

Structural proteins found only in animals

Back 37

Fibrous proteins

Front 38

Generally non-structural proteins that act as transporters (often enzymes) and are usually water soluble

Back 38

Globular proteins

Front 39

Structure of an amino acid

Back 39

Alpha Carbon with a hydrogen, amino group (H2N), carboxyl group (COOH), and a side chain (R)

Front 40

An amino acid dissolved in water that exists as a dipolar ion which can act as an acid or base

Back 40

Zwitterion

Front 41

Substances that have both positive and negative characteristics can be labeled as _______.

Back 41

Amphoteric

Front 42

Chains of less than 40-50 amino acids

Back 42

Polypeptides

Front 43

Covalent bonding between the alpha-carboxyl group and the amino group of another amino acid that link amino acids to form proteins. These bonds are only broken in the presence of high heat and a strong acid or base

Back 43

Peptide bonds

Front 44

This orientation is strongly favored in peptides because of steric interference between the R-groups when in the other orientation.

Back 44

Trans

Front 45

Baseline amino acid sequence in the hierarchy of protein structure

Back 45

Primary structure

Front 46

Regularly repeating local structures stabilized by hydrogen bonds (ie. alpha-helix and beta-sheets)

Back 46

Secondary structure

Front 47

Three dimensional structures formed by the secondary structural elements coming together. Ie. the overall shape of the protein. Have disulfide bonds, hydrophobic interactions, and ionic bonds as well as H-bonding

Back 47

Tertiary structure

Front 48

Secondary structure that is spiral in nature and has a tightly packed, coiled polypeptide backbone core. The side chains of component amino acids try not to cause steric interference with one another. Stabilized by extensive H-bonding

Back 48

Alpha-Helix

Front 49

Secondary structure in which polypeptide sheets are arranged side by side with H-bonding between chains

Back 49

Beta Sheet

Front 50

Secondary structure in which 3 polypeptide chains are woven together. Typical of collagen, connective tissue, cartilage,etc.

Back 50

Triple Helix

Front 51

Covalent linkage formed from the sulfhydryl group (-SH) of two cysteine residues.

Back 51

Disulfide bond

Front 52

Protein structure formed from folded proteins then biding together to form dimer, trimers, or higher order structures. Example is the functional form of hemoglobin

Back 52

Quarternary structure

Front 53

Attractive or repulsive force between molecules (or between parts of same molecule) other than those due to covalent bonds or to the electrostatic interaction of the ions with one another or with neutral molecules. AKA intermolecular forces

Back 53

Van der Waals forces

Front 54

Proteins that assist the non-covalent folding/unfolding and the assembly/disassembly of other macromolecular structures but do not occur in these structures when the latter are performing their normal biological functions

Back 54

Chaperones

Front 55

Energy-dependent degradation system that breaks down endogenous proteins (ie proteins that were synthesized in the cell)

Back 55

Ubiquitin-Protease Mechanism

Front 56

Protein degradation system based on acid hydrolases of the lysosomes

Back 56

Degradative enzymes

Front 57

Denaturation mechanisms of secondary, tertiary, and quaternary protein structure

Back 57

heat; acids/bases; heavy metal ions; agitation

Front 58

Misfolded proteins that aggregate to form beta-plated fibrils. Examples are Alzheimer's and other degenerative diseases

Back 58

Amyloidopathies

Front 59

Proteins that can change the conformation of other proteins. They are infectious agents. Ex: Mad cow disease

Back 59

Prion