Cell Organelles

Question 1

What is the structure and function of the nucleus?

Answer 1

• has double membrane with pores allowing things to enter and leave
• stores DNA and coordinates cell activity

Question 2

What is the structure and function of the nucleolus?

Answer 2

• found within the nucleus. made of proteins and RNA
• produces ribosomes

Question 3

What is the structure and function of the rough endoplasmic reticulum?

Answer 3

• a series of membrane bound sacs called cisternae with ribosomes on the surface
• protein synthesis and folding of proteins

Question 4

What is the structure and function of the smooth ER?

Answer 4

• a series of membrane bound sacs, no ribosomes present
• produces and processes lipids

Question 5

What is the structure and function of the golgi apparatus?

Answer 5

• flat curved fluid-filled sacs surrounded by vesicles
• processes and packages proteins and lipids, produces lysosomes

Question 6

What is the structure and function of the mitochondria?

Answer 6

• bound by double outer membrane, inner membrane folded to increase SA
• site of respiration and ATP production

Question 7

What is the structure and function of the centrioles?

Answer 7

• two hollow cylinders at a right angle, contain micro tubules
• involved in cell division

Question 8

What is the structure and function of the ribosomes?

Answer 8

• composed of 2 sub units, can be membrane bound or in cytoplasm
• site of protein synthesis

Question 9

What is the structure and function of the lysosomes?

Answer 9

• vesicles filled with digestive enzymes and bound by a membrane
• breakdown cell waste and destroy disease causing organisms which enter the cell

Question 10

What is the structure and function of the prokaryotic cell wall?

Answer 10

• forms a rigid outer covering over the cell, made up of peptidoglycan
• provides strength, support and protection against damage

Question 11

What is the structure and function of the capsule?

Answer 11

• thick slimy layer of polysaccharides that covers the cell wall
• prevents cell from drying out, helps adhesion to surfaces

Question 12

What is the structure and function of the plasmid?

Answer 12

• circular molecules of DNA
• DNA replication, transfers DNA between bacteria

Question 13

What is the structure and function of the flagellum?

Answer 13

• long thin projection attached to cell wall
• movement, propels cell forward using corkscrew movemtn

Question 14

What is the structure and function of the pili?

Answer 14

• hair like extensions on the surface of bacterial cells
• help cells adhere to various surfaces like each other

Question 15

What is the structure and function of the mesosomes?

Answer 15

• infolds of the plasma membrane, associated with an enzyme
• site of respiration in prokaryotes

Question 16

How is the rough ER involved in packaging proteins?

Answer 16

• the polypeptide chain passes from ribosome to the RER lumen
• polypeptide chain folds to tertiary structure , passes through RER and can be modified
• finally polypeptide is packaged into a vesicles and transported to the Golgi apparatus

Question 17

How is the Golgi apparatus involved in packaging of proteins?

Answer 17

-Polypeptide travels through Golgi apparatus and may be further modified
- protein is packaged into secretory vesicles which can fuse with cell membrane and protein is secreted from cell

Question 18

How does a TEM work?

Answer 18

Transmission electron microscope - electron beam instead of light, revealing smaller details; use electromagnetic or electrostatic lenses which focus electrons; produces 2D and greyscale images

Question 19

How does a SEM work?

Answer 19

Scanning electron microscope - scan beam of electron across specimen; beam bounces off surface + detects electrons, producing 3D images; images only show specimen surface so don’t have to be as thin

Question 20

Describe differences between SEM and TEM

Answer 20

Images - TEM = 2D, SEM = 3D
Specimen - TEM = thin, SEM = coated with metal
Beam - TEM = goes through sample, SEM = goes across and bounces off
Resolution TEM = Higher, SEM = Lower