Ap Bio Vocab Quiz 4

Front 1

Bacteriophage

Back 1

A virus that transfers its genome to bacteria; used in Hershey and Chase's experiment

Front 2

Ligase

Back 2

Enzyme that closes gaps in DNA during replication after primer is replaced on lagging strand; also used to splice in foreign DNA, creates a bond between nucleotides

Front 3

Polymerase

Back 3

An enzyme that elongates a nucleic acid, either DNA or RNA; binds only to DNA's 3' end, causing leading/lagging strand mechanic; DNA pol. III simply extends DNA, DNA pol. I replaces RNA primers with DNA

Front 4

Helicase

Back 4

Enzyme that untwists DNA molecule at replication forks; assisted by topoisomerase, relieves tension further along the molecule

Front 5

Lagging strand

Back 5

The strand where local DNA elongation occurs opposite the general direction of replication; Okazaki fragments are formed, more enzymes used

Front 6

Leading strand

Back 6

The strand where local DNA elongation and general replication directions match; only one primer, DNA pol. III takes over replication, no need for ligase or pol. I

Front 7

Nuclease

Back 7

Corrects errors in DNA by cutting out erroneous DNA nucleotides, allowing DNA polymerase to fix the error

Front 8

Okazaki fragment

Back 8

A short fragment of DNA in the lagging strand; multiple fragments are created as DNA replication moves further and primers are attached further and further up

Front 9

Primer

Back 9

A short RNA segment added by primase to begin an Okazaki fragment (DNA pol. III cannot function without having a primer to attach to)

Front 10

Replication fork

Back 10

The place where DNA splits to allow replication to continue; begins at replication bubble

Front 11

Semiconservative model

Back 11

Model of DNA replication wherein each new molecule contains one strand of new DNA and one strand from the previous generation; proved by Meselson and Stahl's experiment

Front 12

Telomere

Back 12

The repeated series of nucleotides at the end of DNA that shortens in each replication, preserving a person's life; replenished in germ cells by active telomerase

Front 13

5' cap

Back 13

A modified guanine nucleotide with 3 phosphate groups attached attached to the 5' end during mRNA modification; helps to bind to ribosome, protect against hydrolysis; noncoding

Front 14

Anticodon

Back 14

The 3 nucleotides at one end of a tRNA that bind to the mRNA molecule's codon; the opposite of the codon

Front 15

Codon

Back 15

Series of 3 nucleotides on the mRNA that code for one amino acid; must be in correct reading frame in order to work properly

Front 16

Exon

Back 16

The part of an mRNA molecule that is left after mRNA splicing in the spliceosome; the part that is expressed; opposite of an intron; can be useful in alternative RNA splicing

Front 17

Mutation

Back 17

Changes in genetic material; can be a base-pair substitution, insertion, or deletion; can be passed down via inheritance

Front 18

Intron

Back 18

The segment of DNA that is removed in spliceosomes and not expressed

Front 19

mRNA

Back 19

Messenger RNA, that delivers DNA information to the cytoplasm or endoplasmic reticulum and is transcribed by ribosomes

Front 20

Promoter

Back 20

The sequence in eukaryotes and prokaryotes where the RNA polymerase attaches to DNA and begins transcription; noncoding

Front 21

tRNA

Back 21

Attaches to amino acids at aminoacyl-tRNA synthetase; binds to codon at A site, contains anticodon; responsible for peptide chain elongation

Front 22

Spliceosome

Back 22

Contains snRNPs which contain snRNA; cuts up mRNA, leaving only exons and no introns

Front 23

TATA box

Back 23

Nucleotide sequence containing TATA, upstream from transcription start point, where transcription factors must bind

Front 24

Transcription

Back 24

The process of creating mRNA from DNA; involves a large protein called RNA polymerase II

Front 25

rRNA

Back 25

The most abundant type of RNA; makes up 2/3 of ribosomes, processed and assembled from proteins in the cytoplasm

Front 26

Translation

Back 26

The creation of proteins from mRNA; involves... well, you know the process, basically; I mean, come on, now

Front 27

Triplet code

Back 27

The system of DNA expression where each amino acid is represented by three distinct nucleotides

Front 28

Capsid

Back 28

The outside envelope of a virus, which protects the DNA or RNA inside; virus uses cell's enzymes to produce more capsomeres for new capsids to form

Front 29

Conjugation

Back 29

Bacterial rape; where one bacteria extends its sex pilus, drawing two bacteria close together, and then a mating bridge forms; if F plasmid is present separately, the plasmid is transferred; if it is integrated into the bacteria's genome, recombination results

Front 30

Episome

Back 30

Any DNA that can replicate independently of the bacterial chromosome, such as temperate phages and plasmids

Front 31

Operon

Back 31

A group of genes controlled by one promoter that all relate to the same process; part of the promoter is operator, which repressors can bind to to stop the genes from being expressed

Front 32

Plasmid

Back 32

A small circular self-replicating DNA molecule that can be transferred to a bacteria; can be useful to bacteria in certain environments

Front 33

Prophage

Back 33

The segment of a virus's DNA after it integrates itself into the bacterial genome in the lysogenic cycle

Front 34

Restriction enzymes

Back 34

Enzymes that cut up foreign DNA as part of a bacteria's defense against viruses; cuts DNA at a restriction site, leaving sticky ends; bacteria's own DNA protected naturally via methylation

Front 35

Reverse transcriptase

Back 35

Present in retroviruses; forms a DNA molecule from RNA, allowing the DNA to become a provirus; used in cDNA production

Front 36

Transformation

Back 36

A bacteria's change in genome from uptaking foreign DNA, becoming recombinant via surface proteins that recognize and bring in DNA from similar species

Front 37

Transposable element

Back 37

A length of DNA that moves from one place to another within the chromosome; brought to its new site by folding

Front 38

Cell differentiation

Back 38

The process of cells slowly developing to have a specific purpose, so that only certain genes are expressed

Front 39

Differential gene expression

Back 39

The expression of different genes by cells with the same genome

Front 40

Histone

Back 40

Proteins with tails that form groups of 8; acetylation of these histone tails causes the histones to drift apart, making the chromatin less dense and allowing genes to be expressed

Front 41

Oncogene

Back 41

A gene that facilitates cell replication once it becomes overactive and causes cancer

Front 42

P53 gene

Back 42

Responds to DNA damage by producing a protein that halts the cell cycle by producing P21, turning on DNA repair genes, or (in the case of irreparable DNA damage) causing apoptosis

Front 43

Tumor suppressor gene

Back 43

A gene that produces a protein that inhibits cell division; damaging this gene may lead to increased risk of cancer

Front 44

Apoptosis

Back 44

Cell "suicide"; can lead to the suppression of cancer, when the p53 gene causes apoptosis; can play a role in morphogenesis

Front 45

Cytoplasmic determinants

Back 45

Molecules present in the cytoplasm of an egg that affect the egg's development; usually unevenly distributed, and distributed to different cells, depending on which side the cell was on; contributes to cell differentiation, as nucleus is exposed to different determinants

Front 46

Homeotic genes

Back 46

Genes that specifically help the cells designate which sections of the growing embryo should be where, specifying orientation of parts

Front 47

Morphogenesis

Back 47

Physical processes that give rise to an organism's shape and function, and which cells will become which part of the organism; occurs throughout the life of plants

Front 48

Stem cells

Back 48

Cells that can both reproduce indefinitely and differentiate to any type; examples are bone marrow; adult stem cells are pluripotent, not able to give rise to any cell but able to give rise to multiple ones

Front 49

Totipotent

Back 49

Any cell that has the potential to dedifferentiate and give rise to all other specialized cells in that organism; testable by seeing if the single cell can replicate into a whole organism; tested by FC Steward