DNA,RNA &Protein Synthesis Study Guide

DNA
*Code Of Life
*Contains information on how to make proteins
*Consists of Sugar,a Phosphate,&a Nitrogenous Base
*Bases Are: Adenine, Thymine,Guanine Cytosine

Chromosome
cell structures that carry the genetic material that is copied and passed from generation to generation of cells (threadlike structures)

Gene
The set of information that controls a trait; a segment of DNA on a chromosome that codes for a specific trait (controls protein production and cell cycle)

Deoxyribose
The sugar component of DNA, having one less hydroxyl group than ribose, the sugar component of RNA.

Purine
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) are purines.

Pyrimidine
One of two types of nitrogenous bases found in nucleotides, characterized by a six-membered ring. Cytosine (C), thymine (T), and uracil (U) are pyrimidines.

Replication
(genetics) the process whereby DNA makes a copy of itself before cell division

Helicase
An enzyme that untwists the double helix of DNA at the replication forks, separating the two strands and making them available as template strands.

Polymerase
an enzyme that catalyzes the formation of new DNA and RNA from an existing strand of DNA or RNA

Ligase
An enzyme that connects two fragments of DNA to make a single fragment; also called DNA ligase.

RNA
Ribonucleic acid, a natural polymer that is present in all living cells and that plays a role in protein synthesis.,( nucleic acid molecule that allows for the transmission of genetic information)

Ribose
The sugar molecule of every RNA nucleotide

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
The most abundant type of RNA, which together with proteins froms the structure of ribosomes. Ribosomes coordinate the sequential coupling of tRNA molecules to mRNA codons; also called ribosomal RNA.

ribosome
small particle in the cell on which proteins are assembled; made of RNA and protein

Protein Synthesis
the formation of proteins by using information contained in DNA and carried by mRNA

Amino Acid
building blocks of proteins

Codon
a specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid

Anticodon
A sequence of three bases of a tRNA molecule that pairs with the complementary three-nucleotide codon of an mRNA molecule during protein synthesis.

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

Translation
Making protein in the ribosome.

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

Rosalind Franklin
Woman who generated x-ray images of DNA, she povided Watson and Crick with key data about DNA

Maurice Wilkins
British physicist, used x-ray diffraction and x-ray crystallography to see the make-up of DNA

Watson & Crick
nobel prize winners for correctly describing the structure of DNA as a double helix

Pauling
Linus Pauling’s incorrect model of the DNA structure

Chargaff
The individual responsible for discovering the base pairing rules for DNA.

The structure of DNA
Double helix, two (identical) sides

Base Pairing Rule
the rule stating that in DNA, cytosine pairs with guanine and adenine pairs with thymine and in RNA, adenine pairs with uracil (AG,CT)

Subunits of Nucleic Acid
nucleotides

Structure of a Nucleotide
A nucleotide is a nucleic-acid chain that consists of 3 things: a sugar, a phosphate, and a nitrogen base.

Sugar: deoxyribose
Nitrogen bases: adenine, thymine, cytosine, guanine

Backbone of DNA made of
Phosphate, sugar (deoxyribose), and nitrogen bases

How are nitrogenous bases held together
By Hydrogen

Steps of DNA Replication
1.DNA “unzips” (hydrogen bonds are broken by helicase)
2.new complimentary strands created through help of DNA polymerase
3.DNA polymerase complimentary base pairs new deoxyribonucleotides on each original strand (A-T, G-C)

Leading or Lagging
Leading:The leading strand is the template strand of the DNA double helix so that the replication fork moves along it in the 3′ to 5′ direction. This allows the newly synthesized strand complementary to the original strand to be synthesized 5′ to 3′ in the same direction as the movement of the replication fork.
Lagging:The lagging strand is the strand of the template DNA double helix that is oriented so that the replication fork moves along it in a 5′ to 3′ manner.

WHERE does DNA Replication Occur
in the nucleus.

WHEN does DNA replication Occur
Different types of cells replicated their DNA at different rates. Some cells constantly divide, like those in your hair and fingernails and bone marrow cells. Other cells go through several rounds of cell division and stop (including specialized cells, like those in your brain, muscle and heart). Finally, some cells stop dividing, but can be induced to divide to repair injury (such as skin cells and liver cells)

DNA Replication Is semi-conservative means
each new double stranded DNA molecule: one parental (conserved) strand, one new strand.

Complimentary Strand for a DNA Code

3 Main Differences of DNA and RNA
DNA: double stranded RNA: single stranded
in nucleus out of nucleus
replication translation
lifetime short time

Where RNA is synthesized
-within the nucleus

Where is site of Protein Synthesis
Ribosomes

Whats first: translation or transcription
Transcription

How many nucleotides would code for a protein that is 30 amino acids long
1 codon = 3 nucleotides so 3 X 30 =90

Start Codon
codon that signals to ribosomes to begin translation; codes for the first amino acid in a protein

Stop Codon
Codon that signals to ribosomes to stop translation

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

Frameshift Mutation
mutation that shifts the “reading frame” of the genetic message by inserting or deleting a nucleotide

Lethal Mutation
a mutation that causes death

Mutation that does most damage to a protein design
Frameshift

2 types of point mutation
Missense Mutation
Nonsense Mutation

Missense Mutation
The most common type of mutation, a base-pair substitution in which the new codon makes sense in that it still codes for an 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.