Bacteria structure

Question 1

What is the cell structure of prokaryotes and draw it?

Answer 1

Prokaryotes have 11 things to their structure

1. plasma membrane
2. cell wall
3. capsule
4. pilus
5. flagellum
6. fimbriae
7. cytoplasm
8. ribosome
9. nucleoid
10. inclusion
11. plasmid

Question 2

What are the types of bacterial cell envelope

Answer 2

1. gram negative cells
   - has both an inner and outer membrane
2. gram positive cells
   - has only an inner membrane

Question 3

What is the structure of a plasma membrane

Answer 3

A phospholipid bilayer
- phosphate head (hydrophillic), glycerol body, and fatty acids tail (saturated or unsaturated)

the membrane is semi-permeable and it can freely diffuse small non-polar molecules and hydrophobic molecules

it cannot diffuse polar molecules or charged molecules

Question 4

What are the different types of fatty acids in a phospholipid layer

Answer 4

saturated fatty acids
- they have straight tails
- promotes stiff membrane

unsaturated fatty acids
- unsaturated fatty acids
- have kinked (twisted or curved) tails
- enhances fluidity

hopanoids
- may further stabilize membranes at high temps

Question 5

what are archaea’s lipid layer?

Answer 5

Tetraether lipid since it forms a stable monolayer

they can adapt to high temperatures and the ring further stabilizes it and thus reduced fluidity and causes the membrane to remain stiff

Question 6

what does the cell wall help do?

Answer 6

3 things

1. helps maintain the shape
2. resist osmotic rupture
3. resist harsh conditions

Question 7

which bacteria does not have a cell wall?

Answer 7

mycoplasma

Question 8

what is the cell wall made of?

Answer 8

peptidoglycan (murein)

Question 9

what is a single-celled, with a cell wall but no nucleus. It also does photosynthesis and has ribosomes?

Answer 9

prokaryotes/bacteria

cyanobacteria do photosynthesis

Question 10

What is an organism that is single celled, has two cell membranes around the cell, has a pili and nucleoid, but does not do photosynthesis

Answer 10

Bacteria, gram negative bacteria, prokaryotic

two cell membranes gram negative

Question 11

what organism is single celled with a cell wall, has a nucleus and secretes enzymes into the environment to break down biological molecules and then absorbs them

Answer 11

yeast, (nucleus: a eukaryotic)

Question 12

What organism is multicellular with distinct differentiation of tissues has cell walls, lives on the land and does photosynthesis

Answer 12

Plants (multicellular eukaryotic)

Question 13

What organism is single celled, has a nucleus and does photosynthesis?

Answer 13

Algae (single celled and does photosynthesis)

Question 14

True or false? Archaea may have phospholipid monolayers

Answer 14

True

Question 15

True or false? the cell wall of a bacterial cell is single molecule

Answer 15

true, peptidoglycan (murein)

Question 16

True or false? a gram negative cell has a thick cell wall

Answer 16

false, it has a thin cell wall but it has thick plasma membrane

gram positive cells have thick cell walls

Question 17

True or false? the layers of Mur-NAc and Glc-NAc in peptidoglycan are cross-linked by short glycan chains

Answer 17

False, they are cross-linked by short peptides, the Mur-NAc and Glu-NAc peptidogylcan are the glycan chains

Question 18

True or false? the layer of bacterial cell envelope with the primary responsibility for controlling entry of molecules into the cell is the cell wall

Answer 18

False, it is the plasma membrane that controls entry of molecules

Question 19

Describe two differences between prokaryotes and eukaryotes

Answer 19

1. introns
   prokaryotes: don’t have them

eukaryotes: have them and it helps cut out genes

2. meiosis/mitosis
   prokaryotes: does not do it, does binary fission

eukaryotes: does both

Question 20

fill in the blank:
Archaea can adapt to high temperatures by using a type of phospholipid in their membrane called ____, which has ____ side chains. This causes their membrane to be more ____ (stiff or fluid).

Answer 20

Archaea can adapt to high temperatures by using a type of phospholipid in their membrane called “hopanoids”, which has “methyl” side chains. This causes their membrane to be more “stiff” (stiff or fluid).

Question 21

The region between the cell wall and the plasma membrane is called the

Answer 21

periplasmic space

Question 22

Describe three appendages (only include the things that stick out of the bacteria’s body) found on bacteria and their function

Answer 22

1. flagella
   - helps bacteria swim
2. Pili
   - helps bacteria stay in place
3. fimbriae
   - to hang on to the surface of things

Question 23

True or false? Hopanoids are phospholipids which stabilize bacterial membranes

Answer 23

false