Definitions Flashcards Preview

Biochemistry Review > Definitions > Flashcards

Flashcards in Definitions Deck (335)
Loading flashcards...
1

Absolute configuration

The nomenclature system used for the three-dimensional arrangement of atoms in
isomers; the most common systems are D/L and (R)/(S).

2

Acetal

A carbon atom bonded to an alkyl group, two - OR groups, and a hydrogen.

3

Acetyl-CoA

An important metabolic intermediate that links glycolysis and B-oxidation to the citric acid cycle; can also be converted into ketone bodies.

4

Activation

The conversion of a biomolecule to its active or usable form, such as activation of tRNA with an amino acid or activation of a fatty acid with CoA to form fatty acyl-CoA .

5

Activation energy

The energy required to change the state of a molecule or group of molecules to the transition state; the energy required for a reaction to occur.

6

Active site

The catalytically active portion of an enzyme.

7

Active transport

The movement of a molecule against its concentration gradient with energy investment; primary active transport uses ATP, whereas secondary active transport
uses a favorable transport gradient of a different molecule.

8

Activity

The measure of the catalytic activity of an enzyme, also called the velocity or rate. It is often measured as a vmax and may be analyzed after protein isolation.

9

Activity analysis

The determination of the enzymatic activity of an isolated protein by interaction with a substrate; usually colorimetric in nature.

10

Adenosine triphosphate (ATP)

The primary energy molecule of the body; it releases energy by breaking the bond with the terminal phosphate to form ADP and inorganic phosphate.

11

Adipocyte

A cell specializing in fat storage.

12

Aerobic respiration

A collection of energy-producing metabolic processes that require oxygen, including the citric acid cycle, electron transport chain, and oxidative phosphorylation.

13

Agglutination

Clumping of particles caused by the binding of antibody to target antigen.

14

Aldose

A sugar in which the highest order functional group is an aldehyde; can be categorized by number of carbons (triose, tetrose, pentose, hexose, etc.).

15

Allosteric enzymes

Enzymes that experience changes in their conformation as a result of interactions at sites other than the active site, called allosteric sites; conformational changes may increase or decrease enzyme activity.

16

Alpha helix

An element of secondary structure, marked by clockwise coiling of amino acids around a
central axis.

17

Alternative splicing

The production of multiple different but related mRNA molecules from a single primary transcript of hnRNA.

18

Amino acid

A dipolar compound containing an amino group (- NH2) and a carboxyl group (-COOH).

19

Amphipathic

Having both hydrophilic and hydrophobic regions.

20

Amphoteric

The ability to act as an acid or base.

21

Amplification

Increased transcription (and translation) of a gene in response to hormones, growth factors, and other intracellular conditions.

22

Anabolism

The series of metabolic processes that result in the consumption of energy and the synthesis of molecules.

23

Anaerobic respiration

The series of energy-producing metabolic processes that do not require oxygen, including glycolysis and fermentation.

24

Anomers

A subtype of epimers in which the chiral carbon with inverted configuration was the carbonyl carbon (anomeric carbon).

25

Antibody

A specialized protein molecule produced by lymphocytes for interaction with antigens; antibodies consist of two heavy and two light chains that have constant and variable regions. Antibodies, also called immunoglobulins, are mediators of the immune response.

26

Anticodon

A three-nucleotide sequence on a tRNA molecule that pairs with a corresponding mRNA codon during translation.

27

Antigen

The region of a molecule that interacts with an antibody; in most cases, antigens are proteins.

28

Apoenzyme

An enzyme devoid of the prosthetic group, coenzyme, or cofactor necessary for normal activity.

29

Apolipoproteins

Protein molecules responsible for the interaction oflipo- proteins with cells and the transfer of lipid molecules between lipoproteins; also called apoproteins.

30

Aromaticity

The ability ofa molecule to delocalize pi electrons around a conjugated ring, creating exceptional stability.