College Biology Test #2

Topics: Amino Acids, Proteins, Enzymes(not regulation), and Nucleotides

Amino Acids

Building blocks and monomers of proteins

Basic Formula for an Amino Acid

R-CNH2-COOH

Number of Amino Acids

Only 20 amino acids are used by living things.

Categories of Amino Acids(based on R group properties)

polar uncharged, electrically charged, and apolar.

Protein

Amino acid polymer.

Primary Structure

The order in which amino acids are joined together in a protein.

Secondary Structure

Regular coils and folds formed by hydrogen bonding between amino acids, creating a 2D structure.

Tertiary Structure

The 3D structure of a protein resulting from interactions between R-groups.

quaternary structure

the joining of two or more proteins

Denaturation

The process that changes a protein's preferred conformation, inhibiting or inactivating it(can be permanent or temporary).

Causes of Denaturation

High temperatures, excessive salinity, and changes in pH.

Enzymes

Protein catalysts that facilitate a wide range of biological processes.

Catalyst Properties

Catalysts alter the rate of chemical reactions(usually speeds up) without being consumed and lower the activation energy

Enzyme Function

Depends on an exact conformation.

Enzyme Structure

Consists of a structural region(the enzyme), a binding site, and the substrate

Lock and Key Model

Describes how enzymes function by fitting substrates into their active sites.

Nucleotides

Composed of phosphate, a pentose sugar, and the nitrogenous base(know the order)

Types of Nucleotides

adenine, thymine, uracil, guanine, and cytosine.

Complementary Base Pairing

A binds to T and U; C binds to G.

Nucleotide Polymers

Form DNA and RNA.

ATP

The ultimate energy source for all cell activities.

ATP Structure

Composed of adenosine triphosphate (three phosphate) groups (A-P-P-P).

Energy Release

ATP decays to ADP and releases energy when the unstable P-P bond breaks.

Conformation

the 3 dimensional shape for any given protein, and allows it to function most effectively/efficiently

Ribose Structure

5 Carbons, four of which are bonded to an OH, and the last Carbon is double bonded to an O

Deoxyribose

5 Carbons, one is empty, 3 are single bonded to an OH, and the last is double bonded to an O

Nitrogenous Base

Purines and pyrimidines

Adenine(A)

Ribose OR deoxyribose

Thymine(T)

ONLY deoxyribose

Uracil(U)

ONLY ribose

Guanine(G)

ribose AND deoxyribose

Cytosine(C)

ribose AND deoxyribose

GTP(Guanosine Triphosphate)

Equivalent to ATP, but not used without ATP or even used much at all

Catalyst properties

do not favor a reaction direction, not use up in reaction, and chemically selective

substrate imitators

AGonist: partial enzyme response

ANTagonist: bind, but no response

substrate binding

substrates, agonists, and sometimes antagonists bind weakly and repeatedly attach and reattach

what do catalysts do

lower the activation energy

peptide bond

peptide bond

dipeptides

two amino acids joined by a peptide bond