Chapter 13-14 Vocab Terms

A virus that infects bacteria is called a _, which is made up of the macromolecules _ and __________.

bacteriophage; DNA; Protein

Transformation

When one strain of bacteria is changed by a gene or genes from another strain of bacteria

base pairing rules

rule that describes how nucleotides form bonds in DNA; adenine (A) -> thymine (T), guanine (G) -> cytosine (C)

Adenine (A) pairs with...

Paired with Thymine (T) or Uracil (U) (in the case of RNA)

Guanine (G) is paired with what?

Paired with Cytosine (C)

Chargraff's Rule

# of adenines = # thymines; # of guanines = # of cytosines

Nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

A nucleotide monomer contains...

5-Carbon sugar, a phosphate group, and a nitrogenous base (ATCG/AUCG)

5' (five prime)

End of DNA with phosphate exposed/left hanging

3' (three prime)

End of the DNA strand where there is no phosphate group, but sugar is left exposed/hanging

5' (five prime) to 3' (three prime)

The orientation of nucleotides of a single strand of DNA or RNA.

antiparallel

The opposite arrangement of the sugar-phosphate backbones in a DNA double helix.

semiconservative

the new DNA strand that contains one strand that is old and one that is new

Replication

process of copying DNA prior to cell division

DNA polymerase

Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule

Primase (RNA polymerase)

-Recruited to replication form by helicase -Synthesizes RNA primer -Provides free 3'-OH required by DNA polymerase III for elongation

Lipase

enzyme that breaks down fat

Helicase

-enzyme that unwinds the DNA

• generates 2 single stranded template strands

Telomerase

An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.

Telomeres

DNA at the tips of chromosomes

Eukaryote

A cell that contains a nucleus and membrane bound organelles

Prokaryote

A unicellular organism that lacks a nucleus and membrane bound organelles

DNA

A complex molecule containing the genetic information that makes up the chromosomes. (Deoxyribonucleic acid)

RNA

A single-stranded nucleic acid that passes along genetic messages

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

rRNA

ribosomal RNA; type of RNA that makes up part of the ribosome

RNA primer

short piece of RNA needed for DNA polymerase to start

Griffith's experiment

an experiment carried out using the heat-killed bacteria in mice to discover that a factor in heat-killed, disease-causing bacteria can "transform" harmless bacteria into ones that can cause disease

Avery

Discovered that DNA was responsible for transferring genetic information. Built off Griffith's experiment. Discovered that DNA was the transforming factor.

Hershey-Chase Experiment

Used radioactive material to label DNA and protein; infected bacteria passed on DNA; helped prove that DNA is genetic material not proteins

Watson and Crick

these two scientists figured out that the structure of DNA was a double helix

Topoisomerase

corrects "overwinding" ahead of replication forks by breaking, swiveling, and rejoining DNA strands

Backbone of DNA

made up of alternating sugar and phosphate, bases are attached to the deoxyribose or sugar

Okazaki fragments

Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.

Transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

Translation

Process by which mRNA is decoded and a protein is produced

RNA polymerase

Enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription

Intron

a segment of a DNA or RNA molecule that does not code for proteins and interrupts the sequence of genes

Exon

expressed sequence of DNA, codes for protein, sent to ribosomes, used to build protein at ribosomes

promoter

specific region of a gene where RNA polymerase can bind and begin transcription

RNA editing

direct alteration of one or more nucleotides in an mRNA that has already been synthesized

5' cap

The 5' end of a pre-mRNA molecule modified by the addition of a cap of guanine nucleotide.

3' tail

Addition of 50-250 more adenine nucleotides to the 3' end.

Polypeptide

long chain of amino acids that makes proteins

pre-mRNA

a form of messenger RNA that contains both introns and exons

Splicing

the process of removing introns and reconnecting exons in a pre-mRNA

Codon

three-nucleotide sequence on messenger RNA that codes for a single amino acid (ex: AUG)

peptide bond

covalent bond formed between amino acids

ribosome (small and large subunits)

organelle that coordinates the pairing of tRNAs with their mRNA codons

gene regulation

ability of an organism to control which genes are transcribed in response to the environment

operon

A unit of genetic function common in bacteria and phages, consisting of coordinately regulated clusters of genes with related functions.

operator

Region of DNA that controls RNA polymerase's access to a set of genes with related functions.

homeotic genes

Genes that determine basic features of where a body part is.

Homeobox genes

a type of homeotic gene that consists of short, nearly identical DNA sequences that encode proteins that bind to DNA and tell cells in various segments of the developing embryo what type of structures to make

Hox genes

series of genes that controls the differentiation of cells and tissues in an embryo

TATA box

A promoter DNA sequence crucial in forming the transcription initiation complex.

transcription factors

Collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.

repressor

A protein that suppresses the transcription of a gene.

repressor gene

(Located in another portion of the chromosome) codes for a repressor protein which can bind to the "operator" region

Cell Differentiation / Specialization

process of making cells "different" or "special" in function

For example: some cells are muscle cells, some are bone cells

**differential gene expression - genes turned "on" or "off"

Epigenetics

the study of environmental influences on gene expression that occur without a DNA change

Mutation

A change in a gene or chromosome.

silent mutation

alters a base but does not change the amino acid

point mutation (substitution)

gene mutation in which a single base pair in DNA has been changed

missense mutation

A point mutation in which a codon that specifies an amino acid is mutated into a codon that specifies a different amino acid.

nonsense mutation

A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein.

frameshift mutation

mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide

Mutagen

A chemical or physical agent that interacts with DNA and causes a mutation.

Polyploidy

condition in which an organism has extra sets of chromosomes

chromosomal mutation

A change in the chromosome structure, resulting in new gene combinations.