Ultrastructure of Cells

Question 1

What are prokaryotes?

Answer 1

unicellular organisms that lack membrane-bound organelles

Question 2

What are the 2 types of prokaryotes?

Answer 2

1. Bacteria

2. Archae

Question 3

What are the 9 components of a prokaryotic cell?

Answer 3

1. Cell wall: rigid outer covering, made of peptidoglycan, maintains shape and prevents bursting
2. Slime capsule: thick polysaccharide layer used for protection
3. Flagella: long projections that enable movement
4. Pili: hairlike extensions that enable adherence to surfaces or mediate bacterial conjugation
5. Cell membrane: semi-permeable and selective barrier
6. Cytoplasm: internal fluid, not compartmentalized
7. Nuceloid: region of cytoplasm where DNA is located
8. Plasmids: independent circular DNA molecules
9. 70 Ribosomes: responsible for polypeptide synthesis

Question 4

What is binary fission?

Answer 4

Process by which prokaryotic cells divide

Question 5

What are the 3 steps in binary fission?

Answer 5

1. The bacterial chromosome is replicated
2. Moved to opposite ends of the cell
3. Membrane elongates and pinches off (cytokineses) forming two identical cells

Question 6

What are eukaryotes?

Answer 6

Eukaryotes have a compartmentalized cell structure

Question 7

What are the 4 advantages of compartmentalization?

Answer 7

1. Enzymes and substrates can be concentrated in specific locations
2. Substances hazardous can be bound within membranes
3. pH conditions can be relatively maintained
4. Movement of organelles and their content

Question 8

What are the 10 components of eukaryotes?

Answer 8

1. Nucleus: where DNA is stored and replicated
2. Rough endoplasmic reticulum: synthesizes protein for excretion from cell
3. Golgi Apparatus: processes proteins
4. Smooth endoplasmic reticulum: synthesizes hormones and lipids
5. Mitochondrion: produce ATP for cell
6. Plasma membrane: semi-permeable and selective barrier
7. Vacuole: storage, waste disposal, protection, and growth
   - bigger in plant cells
8. Lysosome: digestive organelle
   - only in animals
9. Cytoskeleton: provides internal structure
10. Chloroplast: site of photosynthesis
    - only in plants

Question 9

What is the function of cell containing many mitochondria?

Answer 9

Typically undertake energy-consuming processes

- Neurons and muscle cells

Question 10

What is the function of cell containing many lysosomes?

Answer 10

Tend to undertake digestive processes

- Phagocytes

Question 11

What is the function of cell containing ER?

Answer 11

Secretory activities

- Plasma cells, exocrine glands

Question 12

What is the function of cell containing chloroplasts?

Answer 12

Undergo photosynthesis