Chapter 5 Part 2: Proteins and Nucleic Acids

Question 1

Catalyst

Answer 1

A chemical agent that selectively increases the rate of reaction without being consumed by the reaction

Question 2

Polypeptide

Answer 2

A polymer of many amino acids linked together by a peptide bond

Question 3

Protein

Answer 3

• A biologically functional molecule

- Consists of one or more polypeptides folded and coiled into a specific three-dimensional structure

Question 4

Amino Acid

Answer 4

• An organic molecule possessing both a carbonyl and an amino group
• Serves as the monomer of polypeptides

Question 5

Primary Structure

Answer 5

The level of protein structure referring to the specific linear sequence of amino acids

Question 6

Secondary Structure

Answer 6

Regions of repetitive coiling or folding of the polypeptide backbone of a protein due to hydrogen bonding between constituents of the backbone (not the side chains)

Question 7

ɑ Helix

Answer 7

A coiled region constituting one form of the secondary structure of proteins, arising from a specific pattern of hydrogen bonding between atoms of the polypeptide backbone (not the side chains)

Question 8

Tertiary Structure

Answer 8

The overall shape of a protein molecule due to interactions of amino acid side chains, including hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bridges

Question 9

Quaternary Structure

Answer 9

The particular shape of a complex, aggregate protein, defined by the characteristic three dimensional arrangement of its constituent subunits, each a polypeptide

Question 10

Hydrophobic interaction

Answer 10

A type of weak chemical interaction caused when molecules that do not mix with water coalesce to exclude water

Question 11

Disulfide Bridge

Answer 11

A strong covalent bond formed when the sulfur of one cysteine monomer bonds to the sulfur of another cysteine monomer

Question 12

Sickle Cell Disease

Answer 12

A recessively inherited human blood disorder in which a single nucleotide change in the β-globin gene causes hemoglobin to aggregate, changing red blood cell shape and causing multiple symptoms in afflicted individuals

Question 13

Denaturation

Answer 13

-Process in which a protein unravels and loses its native shape
-Makes a protein biologically inactive
OR
-Separation of two strands of the double helix in DNA
-Occurs under extreme conditions of pH, salt concentration, and/or temperature

Question 14

Chaperonin

Answer 14

• Also called chaperone protein

- A protein complex that assists in the proper folding of other proteins

Question 15

X-Ray Crystallography

Answer 15

• A technique used to study the three-dimensional structure of molecules
• Depends on the diffraction of an X-ray beam by the individual atoms of a crystalized molecule

Question 16

Gene

Answer 16

• A discrete unit of hereditary information

- Consists of a specific nucleotide sequence in DNA (or RNA in some viruses

Question 17

Nucleic Acid

Answer 17

• A polymer (polynucleotide) consisting of many nucleotide monomers
• Serves as a blueprint for proteins and, through the actions of proteins, all cellular activities
• Two types: DNA and RNA

Question 18

Deoxyribonucleic Acid (DNA)

Answer 18

• A nucleic acid molecule, usually a double stranded helix
• Each polynucleotide strand consists of nucleotide monomers with a deoxyribose sugar and the nitrogenous adenine (A), cytosine (C), guanine (G), and thymine (T)
• Capable of being replicated
• Determines the inherited structure of a cell’s proteins

Question 19

Ribonucleic Acid (RNA)

Answer 19

• Type of nucleic acid consisting of a polynucleotide made up of nucleotide monomers
• The monomers have a ribose sugar and the nitrogenous bases adenine (A), guanine (G), cytosine (C), and uracil (U)
• Usually single-stranded
• Functions in protein synthesis, gene regulation, and as the genome of some viruses

Question 20

Gene Expression

Answer 20

Process where information encoded in DNA directs the synthesis of proteins or in some cases RNAs that just function as RNAs and do not become proteins

Question 21

Polynucleotide

Answer 21

• A polymer consisting of many nucleotide monomers in a chain
• Nucleotides can be those of DNA or RNA

Question 22

Nucleotide

Answer 22

• The building block of a nucleic acid

- Consists of a five-carbon sugar covalently bonded to a nitrogenous base and one or more phosphate groups

Question 23

Pyrimidines

Answer 23

• One of two groups of nitrogenous bases found in nucleotides
• Characterized by a six-membered ring
• Cytosine (C), thymine (T), and uracil (U)

Question 24

Purines

Answer 24

• One of two types of nitrogenous bases found in nucleotides
• Characterized by a six-membered ring fused to a five-membered ring
• Adenine (A) and guanine (G)

Question 25

Deoxyribose

Answer 25

• Sugar component of DNA nucleotides

- Has one or fewer hydroxyl group than ribose

Question 26

Ribose

Answer 26

Sugar component of RNA nucleotides

Question 27

Double Helix

Answer 27

Form of DNA referring to its two adjacent antiparallel polynucleotide strands wound around an imaginary axis into a spiral shape

Question 28

Antiparallel

Answer 28

Referring to the arrangement of the sugar-phosphate backbones in a DNA double helix (they run in opposite 5’-3’ directions)

Question 29

Genomics

Answer 29

Systematic study of whole sets of genes (or other DNA) and their interactions within a species as well as their genome comparisons between species

Question 30

Proteomics

Answer 30

Systematic study of sets of proteins and their properties, including their abundance, chemical modifications, and interactions