Lecture 5

Question 0

Do prokaryote cells have internal membranes?

Answer 0

They have no membrane bound organelles so no

Question 1

What are the features of a prokaryote’s DNA?

Answer 1

• no nucleus

- DNA in unbound region = nucleoid

Question 2

What size are prokaryote cells?

Answer 2

Very small

0.1-5 um

Question 3

What are the 3 shapes a prokaryote can be?

Answer 3

• cocci (balls)
• bacilli (cylinder)
• spirochaetes (worm shapes)

Question 4

How do prokaryote cells move?

Answer 4

Mobile with flagella
Rotary spinning action
- anticlockwise = run
- clockwise = tumble

Question 5

What is the capsule of a prokaryote cell like?

Answer 5

Usually carbohydrate - slippery

Question 6

What does the capsule of a prokaryote prevent?

Answer 6

Desiccation and dehydration

Question 7

What does the capsule of the prokaryote increase?

Answer 7

Resistance to phagocytosis

Adhesion to solid surfaces (colonisation)

Question 8

How much peptidoglycan does gram + bacteria have?

Answer 8

A lot

Question 9

What membranes does a gram + bacteria have?

Answer 9

An inner cell membrane only

Question 10

Does a gram + retain a primary stain?

What colour?

Answer 10

Yes it does

Purple/blue

Question 11

Is a gram + bacteria similar to other cells? What does this mean?

Answer 11

Yes, means it is not ideal for antibiotics

Question 12

How much peptidoglycan does a gram - bacteria have?

Answer 12

Very little

Question 13

What membranes does a gram - have?

Answer 13

An inner and outer membrane

Question 14

Does a gram - bacteria retain a primary stain? What colour?

Answer 14

No it doesn’t

Pink

Question 15

What is the structure of peptidoglycan?

Answer 15

A sugar backbone attached to peptides

Question 16

What is a key feature of peptidoglycan?

Answer 16

It has a strong and impermeable structure

Question 17

Pili (fimbriae) what is it?

Answer 17

Little hair like projections

Question 18

What do fimbriae help?

Answer 18

Adhesion to solid surfaces (disease and biofilm)

Question 19

What do sex pili do?

Answer 19

Allow bacterial conjunction (genetic material exchange)

Question 20

What is a nucleoid in prokaryote’s?

Answer 20

Large loop of DNA

Question 21

Where else is there DNA in prokaryote’s?

Answer 21

The plasmids: short loops of extra chromosomal DNA

Question 22

What does the plasmid DNA do?

Answer 22

• virulence
• resistance to antibiotics
• bacteriocin (natural antibiotic)
• fertility (conjunction)

Question 23

What is an endospore?

Answer 23

Seed like condensed nuclear material

Question 24

When are endospores produced?

Answer 24

In adverse conditions

Question 25

What is the function of an endospore?

Answer 25

Attaches to the nucleoid to protect it from - heat - dryness - chemicals - desiccation

Question 26

How are ribosomes in prokaryote's different to that in eukaryotes?

Answer 26

They are about 50% smaller

Question 27

What in prokaryote's are the target site for antibiotics?

Answer 27

The ribosomes

Question 28

What happens when antibiotics attack ribosomes in prokaryote's?

Answer 28

Inhibition of proteins synthesis in bacteria

Question 29

What is significant about the DNA in eukaryotes?

Answer 29

They're in a double nucleus | - membranous nuclear envelope

Question 30

Do eukaryotes have inner membranes?

Answer 30

Yes because they have membrane bound organelles

Question 31

What does the membrane bound organelles allow?

Answer 31

More complex metabolic reactions

Question 32

What size are eukaryotes?

Answer 32

Much larger than prokaryote's | - 10-100um

Question 33

What is the function of the smooth ER?

Answer 33

- synthesises lipids (eg sex hormones) - detoxifies poisons (eg alcohol) - stores calcium

Question 34

What will a big drinker or alcohol have a lot of?

Answer 34

Smooth ER produced by the liver

Question 35

What is the function of the rough ER?

Answer 35

Has ribosomes bound to it - secretes glycoproteins - sends transport vesicles - manufactures cell membrane

Question 36

What is the structure of Golgi body?

Answer 36

Flattened sacs called cristae

Question 37

What is the function of Golgi body?

Answer 37

- modifies products of ER - manufactures certain macromolecules - sorts/packages materials into transport vesicles - cis/trans faces

Question 38

What is the structure of mitochondria?

Answer 38

- semi-autonomous (contains its own DNA) - double membrane - forms networks

Question 39

What is the function of the mitochondria?

Answer 39

Changes energy from one form to another (sites of cellular respiration)

Question 40

Organelles that animals have that plants don't

Answer 40

- lysosomes - centrosomes with centrioles - flagella (flagellum)

Question 41

Organelles plant cells have that animal cells don't

Answer 41

- chloroplasts (animals can get from eating leaf) - central vacuole/cell wall (plant cell structure/support) - plasmodesmata (communication between plant cells)