Chapter 13 - DNA, Protein Synthesis and Epigenetics

Question 1

What is DNA short for, and where is it found?

Answer 1

Deoxyribonucleic acid and is found in the cells of all organisms, in the nucleus.

Question 2

What does DNA contain?

Answer 2

All the genetic information that determines cell structure and the way it functions

Question 3

What is a Histone?

Answer 3

DNA is bound to and coils around so it can fit into the nucleus of a cell.

Question 4

What is a Chromatin?

Answer 4

In a cell that’s not dividing, the DNA forms a tangled network called Chromatin

Question 5

What is a Gene?

Answer 5

Sections of DNA. They contain genetic code that dictates the structure and functions of the cell.

Question 6

What is a Gene?

Answer 6

Sections of DNA. They contain genetic code that dictates the structure and functions of the cell.

Question 7

Why do body cells need to reproduce?

Answer 7

Growth and Development

Question 8

What does DNA do and how does it do this?

Answer 8

DNA controls the structure and functions of a cell by providing the instructions to make proteins.

Question 9

What is RNA

Answer 9

Ribonucleic acid is a single helix that is similar to mRNA but instead of thymine, uricil is used to complement adenine

Question 10

What does RNA polymerase do

Answer 10

RNA Polymerase is an enzyme that creates mRNA which copies one strand (template strand) of DNA.

Question 11

What happens to completed mRNA strands

Answer 11

They move into the cytoplasm through the nuclear pores.

Question 12

What is Translation

Answer 12

The production of a protein using information that is coded in the mRNA molecule

Question 13

Explain the Process of Translation

Answer 13

A ribosome attaches to one end of the mRNA
Ribosome reads three bases at a time
Each set of three is code for an amino acid and is called a codon
Codon AUG - is the start codon
Ribosomes only start making Proteins when they reach Aug
transfer RNA bring individual amino acids to the ribosome
The anticodon determines the amino acid carried
As the ribosome reads the codon on the mRNA, tRNA molecules with the matching anticodon is brought in

Question 14

What is the difference between Mitochondrial DNA and Nuclear DNA

Answer 14

mtDNA is found in the mitochondria in the form of small circular molecules that are not bound to proteins whereas nuclear DNA is found in the nuclear in the form of a very long stands that are bound to histones

Question 15

What is Gene Expression

Answer 15

The transcription and translation process. Cells make mRNA from only a fraction of its genes

Question 16

What is Epigenetics?

Answer 16

Change in gene expression in that result from mechanisms often changes in genes (DNA)

Question 17

What is Epigenome?

Answer 17

All the factors that determine when, where and which genes are expressed

Question 18

Define Acetylation

Answer 18

The addition of an acetyl group to the histone, this enhances gene expression

Question 19

Define Methylation

Answer 19

The addition of methyl groups to the DNA, this inhibits (prevents) gene expression.
- Usually where C is next to G = aka CpG sites.

Question 20

What environmental factors can influence the change of epigenomes?

Answer 20

Severe stress, nutritional factors, toxins or drugs. Interfere with transcription and translation