DNA and RNA Study Guide

What does DNA stand for?

What does DNA stand for?

Deoxyribonucleic acid

What are the three parts of the nucleotide?

Nitrogenous base, Deoxyribose (sugar), and phosphates

What are the four bases found in DNA?

Adenine, Thymine, Guanine, Cytosine

How do the bases pair up (what pairs w/ what)?

A = T, G = C

What is the sugar found in DNA called?

Deoxyribose

What is the shape of the DNA molecule?

Double Helix

What is the type of bond that holds the base pairs together? What makes up the backbone of the DNA molecule (the sides of the ladder)?

Hydrogen Bonds hold bases together, Covalent Bonds hold the backbone together.

What are the steps of DNA replication? Be sure to include the names of the enzymes involved.

1. Helicase unwinds DNA strands by breaking hydrogen bonds connecting the bases

2. DNA Polymerase adds bases following base pair rules

3. Two new molecules are made - each with one original and one new strand

DNA replication is called semi-conservative, what does that mean?

Each new molecule has one original strand saved and one new strand created

Why does a cell need to replicate its DNA?

When the cell divides, the two new cells need their own copy of DNA.

What are the three differences between RNA and DNA?

DNA - Double Stranded, has Thymine, and has Deoxyribose

RNA - Single Stranded, has Uracil, and has Ribose

What does RNA stand for?

Ribonucleic acid

What are the three types of RNA and what is their function?

mRNA - Carries messages from DNA to Ribosomes (holds the codons which are read by the tRNA)

tRNA - is inside the ribosome and makes it up, reads the strand of mRNA to produce amino acids. (reads codon and makes complementary bases to create amino acids)

rRNA - Makes up the ribosome and gives it structure

How many nucleotides does it take to make one amino acid?

3

Where are proteins built? (on which cell organelle?)

Ribosomes

Where does transcription take place and what happens?

DNA ----> RNA, happens in the nucleus

What is the process called that changes DNA to mRNA?

Transcription

What is the process called that uses tRNA to carry amino acids to mRNA to build a polypeptide?

Translation

What are the complementary bases in DNA Replication?

DNA to DNA

A = T

T = A

G = C

C = G

What are the complementary bases in DNA transcription?

DNA to mRNA

A = U

T = A

G = C

C = G

Where does translation take place and what happens?

RNA → PROTEIN, In the ribosomes in the cytoplasm

Describe the mutations:

Deletion - Base (Letter) is removed

Frameshift - Insertion or deletion that is not a multiple of three bases, results in alteration of the amino acids starting from the mutation

Missense - Changes one amino acid (Letter)

Silent - Base changes but does not affect the intended amino acids

Nonsense - Adds a STOP codon anywhere in the sequence

Insertion - Base is added

Label the structures

 mRNA 1

 tRNA 5

 amino acid 3

 ribosome  2

polypeptide (protein) 4

DNA replication results in

2 DNA molecules that each contain a strand of the original.

What are the units that form a DNA molecule?

Nucleotides

Which mutation is being illustrated?

Normal: GUG-UGA-CGC-UGU-CCA

Mutated: GGG-UGA-CGC-UGU-CCA

Substitution

In the sequence TAC GGA, what do the letters represent?

Nitrogenous Bases