Unit 1.2

Question 1

Proteome

Answer 1

The entire set of proteins expressed by a genome, this is larger than the number of genes as more than one protein can be produced by a single gene through alternative RNA splicing

Question 2

Alternative RNA splicing

Answer 2

Introns are removed and exons are retained

Question 3

Non-coding RNA genes

Answer 3

These include those that are transcribed to produce tRNA, rRNA and RNA molecules that control the expression of other genes, or any genes that dont code for proteins

Question 4

What factors affect the proteins expressed by a given cell type?

Answer 4

the metabolic activity of the cell, cellular stress, the response to signalling molecules and diseased versus healthy cells

Question 5

What are Eukaryotes

Answer 5

These are cells that have a clearly defended nucleus

Question 6

What is special about Eukaryotes surface to volume ratio?

Answer 6

They have a small enough surface to volume ratio which means there is not enough membrane to preform all the vital functions. For this reason there is also a system of intracellular membranes which help with protein synthesis and transport in the cell

Question 7

What organelles are membrane bound?

Answer 7

-Endoplasmic reticulum
-Golgi apparatus
-vesicles
-Lysosomes

Question 8

Endoplasmic reticulium

Answer 8

This is a series of membrane tubules that extend from the nuclear membrane. Rough endoplasmic reticulum has ribosomes attached along its surface where soother does not.

Question 9

Golgi apparatus

Answer 9

This is a series of flattened membrane disks that proteins pass through to be modified

Question 10

Lysosomes

Answer 10

These contain hydroloses which are enzymes, these enzymes breakdown proteins, lipids, nucleic acids and carbohydrates. Hydroloses use water to break the covalent bonds in these substances

Question 11

Vesicles

Answer 11

These are membrane bound organelles that transport proteins and other substances around the cell

Question 12

What are membranes composed of?

Answer 12

Both lipids and proteins which are synthesized within the cell at the endoplasmic reticulum

Question 13

What is the purpose of a lipid?

Answer 13

Lipids are key components of the plasma membrane and from the hydrophobic lipid tails of the phospholipid bi-layer

Question 14

Where are lipids synthesized?

Answer 14

Lipids are synezied in the smooth endoplasmic reticulum and inserted into the membrane

Question 15

What is cytosol?

Answer 15

The fluid which the organelles are suspended

Question 16

What is the cytoplasm?

Answer 16

Cytosol and all the organelles (not the nucleus) within the plasma membrane

Question 17

What does a signal sequence do?

Question 18

What is responsible for determining the final location of a protein in a cell?

Answer 18

The signal sequence

Question 19

Describe the structure of the Golgi apparatus

Answer 19

This is a series of flattened membrane disks that proteins can pass through to be modified, the proteins move from one disk to the next in the vesicles that bud of and fuse with the next membrane

Question 20

Major post translation modification that occurs in the Golgi

Answer 20

The major example of a post translational modification is the addition of carbohydrates to form a glycoprotein. Enzymes catalyse the addition of various sugars in my,triple steps to form the carbohydrates

Question 21

What is the role of transmembrane proteins?

Answer 21

They carry the protein from the RER membrane and fuses with the Golgi

Question 22

Where do vesicles go when they leave the Golgi apparatus?

Answer 22

To the plasma membrane and lysosomes

Question 23

What is the cytoskeleton microtubles?

Answer 23

What the vesicles move along