Biology Lecture 2: Genes

Front 1

Gene

Back 1

A series of DNA molecules that code for the production of a single polypeptide of mRNA, rRNA, or tRNA

Front 2

Eukaryote

Back 2

Cells contain a nucleus

Front 3

Prokaryote

Back 3

Cell does not contain a nucleus

Front 4

Genome

Back 4

The entire DNA sequence of an organism

Front 5

Central Dogma
of gene expression

Back 5

DNA is transcribed to RNA which is translated to amino acids forming a protein

Front 6

DNA

Back 6

Polymer of nucleotides, AT (2 hydrogen bonds), GC (3 hydrogen bonds)

Front 7

Purines

Back 7

Adenine and Guanine; two-ring structures

Front 8

Pyrimidines

Back 8

Cytosine and Thymine; single ring structures

Front 9

Phosphodiester bond

Back 9

Binds nucleotides of a single strand of DNA with a 5' -> 3' directionality

Front 10

DNA replication

Back 10

Semiconservative, creation of a new double strand contains one strand of original DNA and one newly synthesized strand

Front 11

Replication

Back 11

A bidirectional process that begins in the middle of a strand

Front 12

DNA polymerase

Back 12

Enzyme that builds the new DNA strand by adding nucleotides to an existing strand

Front 13

RNA primer

Back 13

Initiates the new strand

Front 14

Leading strand

Back 14

Continuous replication

Front 15

Lagging strand

Back 15

Discontinuous replication; Okazaki fragments

Front 16

RNA

Back 16

Single stranded, uracil instead of thymine

Front 17

mRNA

Back 17

Delivers the DNA code for amino acids to the cytosol where proteins are manufactured

Front 18

rRNA

Back 18

Combines with proteins to form ribosomes which direct the synthesis of proteins in the nucleolus

Front 19

tRNA

Back 19

Collects amino acids in the cytosol and transfers them to the ribosomes for incorporation

Front 20

Transcription

Back 20

Synthesis of RNA using a DNA template

Front 21

Initiation

Back 21

The beginning of transcription

Front 22

RNA polymerase

Back 22

An enzyme that catalyzes the synthesis of an RNA strand from a DNA template; Prokaryotes 1, Eukaryotes 3

Front 23

Promoter

Back 23

Sequence of DNA nucleotides that designates a beginning point for transcription

Front 24

Elongation

Back 24

RNA polymerase transcribes only one strand of the DNA nucleotide sequence into a complementary RNA nucleotide sequence

Front 25

Termination

Back 25

The end of transcription

Front 26

Operon

Back 26

The genetic unit of an operator, promoter, and genes that contribute to a single prokaryotic mRNA

Front 27

5' cap

Back 27

Attachment site in protein synthesis and protection against exonucleases

Front 28

Poly A tail

Back 28

On the 3' end, protects against exonucleases

Front 29

Intron

Back 29

A polynucleotide sequence in a nucleic acid that does not code information for protein synthesis and is removed before translation of mRNA

Front 30

Exon

Back 30

A polynucleotide sequence in a nucleic acid that codes information for protein synthesis and that is copied and spliced together with other such sequences to form mRNA

Front 31

Nucleic acid hybridization

Back 31

DNA-DNA, DNA-RNA, RNA-RNA

Front 32

Restriction enzymes

Back 32

Cut certain nucleotide sequences along the chain to protect against viruses

Front 33

Palindromic sequence

Back 33

Four to six nucleotides long; restriction site

Front 34

Recombinant DNA

Back 34

Two DNA fragments cleaved by the same endonuclease can be joined together regardless of the origin of the DNA

Front 35

Vector

Back 35

Carrier; Plasmid or infective virus

Front 36

Plasmid

Back 36

A chromosomal ring of DNA that replicates autonomously and is found especially in bacteria

Front 37

Complementary DNA (cDNA)

Back 37

Cloned DNA with no introns, reverse transcribed using reverse transcriptase

Front 38

Polymerase Chain Reaction (PCR)

Back 38

Amplifying specific DNA segments which exploits certain features of DNA replication

Front 39

Small nuclear ribonucleoproteins (snRNPs "snurps")

Back 39

Component of the spliceosome, removes introns in eukaryotic nuclei

Front 40

Anneal

Back 40

Formation of a double helix

Front 41

Southern blot

Back 41

Identifies target fragments of known DNA sequence in a large population of DNA

Front 42

Northern blot

Back 42

Identifies RNA fragments

Front 43

Western blot

Back 43

Detects a particular protein with antibodies in a mixture of proteins

Front 44

Restriction fragment length polymorphisms (RFLP)

Back 44

Variation in DNA fragment banding patterns of electrophoresed restriction sites of DNA from different individuals of a species

Front 45

Start codon

Back 45

AUG

Front 46

Stop codons

Back 46

UAA, UAG, UGA

Front 47

Genetic

Back 47

Four different nucleotides that code for the 20 possible amino acids

Front 48

Translation

Back 48

Protein synthesis directed by mRNA

Front 49

Anticodon

Back 49

A triplet of nucleotide bases in tRNA that binds to a complementary codon in mRNA during protein synthesis at a ribosome

Front 50

Ribosome

Back 50

A sphere-shaped structure within the cytoplasm of a cell that is composed of RNA and protein and is the site of protein synthesis

Front 51

Nucleolus

Back 51

An organelle found in the nucleus, containing rRNA and multiple copies of the genes coding for rRNA

Front 52

Peptidyl site (P site)

Back 52

A three nucleotide position in a ribosome in which peptidyl tRNA is found

Front 53

Aminoacyl site (A site)

Back 53

Occupied by an aminoacyl- tRNA just prior to peptide bond formation

Front 54

Single peptide

Back 54

20 amino acid sequence

Front 55

Post-translational modifications

Back 55

Sugars, lipids, or phosphate groups may be added to amino acids

Front 56

Signal-recognition particle (SRP)

Back 56

Protein RNA that carries the entire ribosome complex to a receptor protein on the ER

Front 57

Mutation

Back 57

Any alteration in the genome that is not a genetic recombination

Front 58

Mutagen

Back 58

A physical or chemical agent that increases the frequency of spontaneous mutations

Front 59

Missense mutation

Back 59

Base-pair mutation that occurs in the amino acid coding sequence of a gene

Front 60

Insertion/Deletion

Back 60

A type of point mutation that results in a frameshift mutation

Front 61

Nonsense mutation

Back 61

Created by a base-pair substitution, insertion or deletion and creates a stop codon (preventing translation)

Front 62

Inversion

Back 62

The orientation of a section of DNA is reversed on a chromosome

Front 63

Wild type

Back 63

The original state of the organism free of mutations

Front 64

Cancer

Back 64

Unrestrained and uncontrolled growth of cells

Front 65

Tumor

Back 65

A mass of cancer cells

Front 66

Metastasis

Back 66

Cancer cells establish tumors in other parts of the body

Front 67

Oncogene

Back 67

A gene having the potential to cause a normal cell to become cancerous

Front 68

Carcinogen

Back 68

Mutagens that cause cancer

Front 69

Histones

Back 69

Any of several proteins that, together with DNA, make up most of the chromatin in a cell nucleus

Front 70

Carcinogen

Back 70

Mutagens that cause cancer

Front 71

Nucleus of human cells

Back 71

46 chromosomes

Front 72

Diploid

Back 72

Any cell that contains homologous pairs

Front 73

Haploid

Back 73

Single/simple unpaired cells

Front 74

Cell Life Cycle

Back 74

Four stages
1. Growth phase (G1)
2. Synthesis (S)
3. Second growth phase (G2)
4. Mitosis or Meiosis and Cytokinesis (C)

Front 75

Mitosis

Back 75

Nuclear division without genetic change (Pro, Meta, Ana, Telo)

Front 76

Meiosis

Back 76

Double nuclear division which produces four haploid gametes (germ cells)