Cells And organelles

Question 1

Describe the plasma (cell surface) membrane

Answer 1

Mainly made of lipids and proteins

Membrane is found on surface of animal cells and just inside the cell wall of plant cells

Question 2

What is the function of the plasma (cell surface) membrane?

Answer 2

• Regulates the movement of substances into and out of the cell.
• has receptor molecules which allow it to respond to chemicals like hormones

Question 3

Describe the cell wall

Answer 3

A rigid structure that surrounds plant cells.

Mainly made of cellulose (a carbohydrate)

Question 4

What is the function of the cell wall

Answer 4

Supports plant cells

Question 5

Describe the nucleus

Answer 5

A large organelle surrounded by a nuclear envelope (double membrane)

Contains chromatin (made from DNA and proteins)

Contains nucleolus

Question 6

What is the function of the nucleus

Answer 6

Controls the cells activities (by controlling the transcription of DNA)

The pores allow substances (E.G.RNA) to move between the nucleus and the cytoplasm

The nucleolus makes ribosomes

Question 7

Describe the lysosome

Answer 7

A round organelle surrounded by a membrane, with no clear internal structure

Question 8

What is the function of the lysosome

Answer 8

Contains digestive enzymes

Can be used to digest invading cells or to break down worn out components of the cell

Question 9

Describe the ribosome

Answer 9

A very small organelle that either floats free in the cytoplasm or is attached to the rough endoplasmic reticulum

Made up of proteins and RNA

not surrounded by a membrane

Question 10

What is the function of ribosomes

Answer 10

Site where proteins are made

Question 11

Describe the rough endoplasmic reticulum

Answer 11

A system of membranes enclosing a fluid filled space

Surface is filled with ribosomes

Question 12

What is the function of the Rough Endoplasmic Reticulum

Answer 12

Folds and processes protein that have been made at the ribosomes

Question 13

Describe the smooth endoplasmic reticulum

Answer 13

System of membrane enclosing a fluid filled space

No ribsomes

Question 14

What is the function of the smooth endoplasmic reticulum

Answer 14

Synthesizes and processes lipids

Question 15

Describe the vesicle

Answer 15

A small fluid filled sac in the cytoplasm surrounded by a membrane

Question 16

What is the function of the vesicle

Answer 16

Transports substances in and out of the cell (via the plasma membrane)

Formed at the golgi or endoplasmic reticulum
While others are formed at the cell membrane

Question 17

Describe the golgi apparatus

Answer 17

A group of fluid filled membrane bound
Flattened sacs
Seen at the edge of the cell

Question 18

What is the function of the Golgi apparatus

Answer 18

Processes and packages new lipids and proteins

Makes lysosomes

Question 19

Describe the mitochondrion

Answer 19

Oval shaped
Double membrane - inner is folded to form structures called cristae
Inside is the matrix which contains enzymes involved in respiration

Question 20

What is the function of the mitochondrion

Answer 20

Site of aerobic respiration where ATP is producer

Found in large numbers in cells that are very active and require a lot of energy

Question 21

Describe the chloroplast

Answer 21

Small flattened structure in plants
Surrounded by a double membrane
Has thylakoid membrane inside which are stacked up to form grana

Grabs are linked together lamellae

Question 22

What is the function of the chloroplast

Answer 22

Site where photosynthesis takes place

Reactions happens in the grana or stroma

Question 23

Describe the centriole

Answer 23

Small , hollow cylinders made of microtubules

Found in all animal but only some plant cells

Question 24

What is the function of the centriole

Answer 24

Involved with the separation of chromosomes during cell division

Question 25

Describe the cilia

Answer 25

Small hair like structures found on the surface membrane of some animal cells.
Ring of nine pairs of protein microtubules inside with 2 microtubules in the middle

Question 26

What is the function of cilia

Answer 26

Microtubules allow the cilia to move

The movement is used by the cell to move substances along the cell surface

Question 27

What organelles do plant cells have that animal cells do not

Answer 27

Chloroplast, Plasmodesma, Vacuole, Cell wall

Question 28

State the function of the two organelles - mitochondria and Golgi apparatus

Answer 28

Mitochondria is the site of aerobic respiration

Golgi apparatus processes and packages proteins, lipids. It also makes lysosomes

Question 29

How are organelles involved in protein production

Answer 29

Transcription of DNA to mRNA
mRNA leaves the nucleus 
protein is made at ribosome on RER
Protein enters RER
transported by vesicles 
Vesicles fuse with Golgi apparatus 
Proteins are modified in Golgi 
Secretory Vesicles transport the protein
Membrane of vesicle and membrane of cell fuses (exocytosis) 
Proteins are expelled

Question 30

What are the four main functions of cytoskeleton

Answer 30

support the cell’s organelles
strengthen the cell and maintain its shape
responsible for movement of materials within the cell
Can cause the cell the move e.g. cilia

Question 31

What is the difference between prokaryotes and eukaryotes

Answer 31

Prokaryotes are smaller 
DNA is circular whereas in eukaryotes DNA is linear 
No nucleus is prokaryotes 
Cell wall is made of polysaccharide 
Small ribosome 
No membrane bound organelles

Question 32

What are the similarities and differences between laser confocal and light microscopy.

Answer 32

They both use light
Laser confocal can view objects at different depths, laser beams is used to scan a specimen which is tagged with a fluorescent dye.

Question 33

what is the resolution and magnification for light microscope, TEM and SEM

Answer 33

Resolution for light - 0.2micrometers
SEM - 0.002 micrometers
TEM - 0.0002 micrometers

Magnification
Light - x1500
SEM - X500,000
TEM - 1,000,000