Cells (lecture 2,3,4)

Question 1

What do all cells have??

Answer 1

Plasma membrane
DNA region
Cytoplasm

Question 2

What type of cell is a prokaryotic cell and provide some details of the structure

Answer 2

A bacteria cell

No membrane bound nucleus or organelles

Question 3

What type of cells are eukaryotic and provide a description

Answer 3

Animal and plant cells

True nuclei
Membrane bound organelles

Has a cytoskeleton

Question 4

What are functions of the plasma membrane?

Answer 4

• to facilitate glucose, fuels etc
• to prevent harmful things getting in and prevent key things leaving
• acts as a phospholipid bilayer, for things to pass they must be lipid soluble

Question 5

What does the nucleus do?

Answer 5

Stores and transmits genetic information in the form of DNA.

Genetic info as messenger RNA can pass from the nucleus into the cytoplasm

Question 6

What is cristae?

Answer 6

The inner membrane of the mitochondria, aims to increase surface area for the electron transport chain to occur

Question 7

Mitochondria is the site for what processes?

Answer 7

Major site of ATP production

Where oxidative phosphorylation occur

Question 8

What does the Golgi apparatus do?

Answer 8

It’s function is to sort, concentrate and modify newly synthesised proteins prior to secretion from the cell

Question 9

What are lysosomes?

Answer 9

Membrane bound vesicles that contain hydrolytic enzymes that are involved in intracellular digestion

Question 10

Are the tails or the heads of the phospholipid bilayer hydrophobic?

Answer 10

The tails are hydrophobic

Question 11

We know simple diffusion occurs down a gradient, but what are some factors affecting the rate?

Answer 11

• the size of the molecule
• lipid solubility
• concentration and electrical potential difference
• temperature
• SA of the membrane available

Question 12

How does facilitated diffusion occur?

Answer 12

When a molecule is too large or not lipid soluble, In the example of a protein carrier, a conformational change in the carrier-solute complex occurs to move the solute across the membrane

Question 13

How are pumps different than say a protein carrier in facilitated diffusion?

Answer 13

Pumps concert energy to allow movement

Pumps work against a gradient

Question 14

What is active transport?

Answer 14

Where substances are moved against a concentration gradient using a protein carrier and energy supplied by ATP or indirectly by ion electrochemical gradients

Question 15

Explain the sodium-potassium ATPase pump?

Answer 15

An example of active transport where 3 sodium moved out of the cell and 2 potassium moved into the cell fueled by ATP.

Sets up an ionic gradient for movement of solutes across membrane

Question 16

What is active co-transport?

Answer 16

Where the concentration gradient of one of the substances is used to facilitate the transport of a different substance against its concentration gradient. Example being sodium dragging in glucose in the gut

Question 17

What is osmosis?

Answer 17

The net movement of water across a membrane as a consequence of a total solute particle concentration difference across a membrane

Question 18

What will happen in a hypertonic and hypotonic solution?

Answer 18

The cell will shrink and swell respectively

Question 19

What is EIB?

Answer 19

Exercise induced bronchoconstruction due to airway narrowing due to an increased influx of epithelial cells

Question 20

Explain cardiac muscle?

Answer 20

I’m cardiac muscle, the adjacent cells are linked by electrically conducting junctions, the cells contract in synchrony