Bio Ch 12

Question 0

Pyrimidine

Answer 0

thymine & cytosine (single ring)

Question 1

Purine-based nucleotides

Answer 1

adenine & guanine (double ring)

Question 2

Double helix

Answer 2

double spiral; describes the 3D shape of DNA

Question 3

Complementary base pairing

Answer 3

a purine (large, 2-ring base) is always bonded to a pyrimidine (smaller, one-ring base)

Question 4

DNA Replication

Answer 4

process of copying a DNA molecule

Question 5

Template

Answer 5

most often a mold used to produce a shape complementary to itself

Question 6

Semiconservative replication

Answer 6

each daughter DNA double helix contains an old strand from the parental DNA double helix and a new strand

Question 7

DNA Polymerase

Answer 7

during replication, an enzyme that joins the nucleotides complementary to a DNA template

Question 8

telomeres

Answer 8

special nucleotide sequence that does not code for proteins; use a repeat sequence such as TTAGGG

Question 9

Replication fork

Answer 9

in eukaryotic DNA replication, the location where the 2 parental DNA strands separate

Question 10

Uracil

Answer 10

in RNA, this base replaces the thymine found in DNA

Question 11

Messenger RNA (mRNA)

Answer 11

takes a message from DNA in the nucleus to the ribosomes in the cytoplasm

Question 12

Transfer RNA (tRNA)

Answer 12

transfers amino acids to the ribosomes

Question 13

Ribosomal RNA (rRNA)

Answer 13

along with ribosomal proteins, makes up the ribosomes, where polypeptides are synthesized

Question 14

Transcription

Answer 14

process by which an RNA molecule is produced based on a DNA template; DNA is copied, base by base, into mRNA, tRNA, & rRNA

Question 15

Translation

Answer 15

mRNA transcript is read by a ribosome and converted into the sequence of amino acids in a polypeptide

Question 16

Central Dogma of Molecular Biology

Answer 16

Flow of info from DNA to RNA to protein to trait

Question 17

Genetic Code

Answer 17

universal code that has existed for eons and allows for conversion of DNA and RNA’s chemical code to a sequence of amino acids in a protein; each codon consists of three bases that stand for one of the 20 amino acids found in proteins or directs the termination of translation

Question 18

Triplet code

Answer 18

each coding unit (codon) would need to be made up of 3 nucleotides

Question 19

Codon

Answer 19

3-base sequence in messenger RNA that during translation directs the addition of a particular amino acid into a protein or directs termination of the process

Question 20

RNA Polymerase

Answer 20

joins nucleotide strands together in the 5’ to 3’ direction

Question 21

Promoter

Answer 21

defines the start of transcription, the direction of transcription, & the strand to be transcribed

Question 22

mRNA transcript

Answer 22

mRNA molecule formed during transcription that has a sequence of bases complementary to a gene

Question 23

Exons

Answer 23

protein-coding regions

Question 24

introns

Answer 24

non-protein coding regions

Question 25

Ribozyme

Answer 25

enzyme made of RNA rather than just protein used to cut and remove introns

Question 26

Anticodon

Answer 26

group of 3 bases that is complementary and antiparallel to a specific mRNA codon

Question 27

Wobble Hypothesis

Answer 27

1966, Francis Crick: 1st 2 positions in a tRNA anticodon pair obey he A-U/G-C configuration rule; 3rd position can be variable; helps ensure that despite changes in DNA base sequences, the resulting sequence of amino acids will produce a correct protein (1 of reasons genetic code is said to be degenerate)

Question 28

Polyribosome

Answer 28

entire complex of mRNA and multiple ribosomes is called this; greatly increases the efficiency of translation

Question 29

Initiation

Answer 29

step that brings all the translation components together

Question 30

Elongation

Answer 30

stage during protein synthesis when a polypeptide increases in length one amino acid at a time

Question 31

Translocation

Answer 31

ribosome moves forward, peptide-bearing tRNA is now in the P site of the ribosome

Question 32

Termination

Answer 32

final step in protein synthesis

Question 33

Proteomics

Answer 33

field of biology dedicated to understanding the structure of proteins and how they function in metabolic pathways

Question 34

Histones

Answer 34

group of proteins involve in forming the nucleosome strucure of eukaryotic chromatin

Question 35

Nucleosome

Answer 35

in the nucleus of a eukaryotic cell, a unit composed of DNA wound around a core of 8 histone proteins, giving the appearance of a string of beads

Question 36

Euchromatin

Answer 36

active chromatin containing genes that are being transcribed

Question 37

Heterochromatin

Answer 37

highly compacted chromatin that is not accessible for transcription