cellular structure and function

Question 1

What structural features does a eukaryotic cell have? What are eukaryotes?

Answer 1

• Nucleus bound by a nuclear envelope (double membrane)
• Many different membrane-bound organelles
• All plants, animals, fungi, protoctista are eukaryotes

Question 2

What structural features does a prokaryotic cell have? What are prokaryotes?

Answer 2

• No true nucleus, a single, circular chromosome in the cytoplasm (nucleoid)
• Peptidoglycan cell wall
• Unicellular and small (1-5 nanometers in diameter)
• Lack membrane-bound organelles
• Bacteria are a prokaryote

Question 3

What are some PTP comparison of prokaryotic and eukaryotic cells?

Answer 3

• P: cells are extremely small, E: cells are relatively larger
• P: nucleoid (no nucleus), E: nucleus
• P: no membrane-bound organelles, E: many membrane-bound organelles

Question 4

What is the function of vacuoles (animal and plant cell)?

Answer 4

(Animal) temporary stores of food/water

(Plant) stores nutrients, absorbs water and involved in turgidity

Question 5

What is the function of the cytoplasm?

Answer 5

It is the site where substances are formed and used in chemical reactions of life

Question 6

What is the function of a cellulose cell wall?

Answer 6

It encloses, supports, protects cells

Question 7

What is the function of a cell surface membrane?

Answer 7

It forms a barrier across which all substances entering and leaving the cell must pass

Question 8

What is the function of mitochondria?

Answer 8

It is the site of aerobic stages of respiration and synthesis of ATP

Question 9

What is the function of chloroplasts?

Answer 9

Site of photosynthesis by which light is used as the energy source in carbohydrate and ATP synthesis

Question 10

What is the function of the smooth endoplasmic reticulum?

Answer 10

It is the site of synthesis of lipids and steroids, and reproductive hormones

Question 11

What is the function of the rough endoplasmic reticulum?

Answer 11

It has ribosomes attached to the outer surface are the sites of synthesis of proteins that are “packaged” into vesicles that fuse with the Golgi apparatus and are then typically discharged from the cell

Question 12

What is the function of the smooth endoplasmic reticulum?

Answer 12

Site of synthesis of lipids and steroids, and reproductive hormones

Question 13

What is the function of the Golgi apparatus?

Answer 13

It is the site of synthesis of specific biochemicals such as hormones or enzymes

Question 14

What is the function of ribosomes?

Answer 14

It is the sites of synthesis of proteins in cells

Question 15

Structural features to function: red blood cell

Answer 15

• Contains haemoglobin, which binds to oxygen and transports it around the body
• Circular, biconcave in shape to increase surface area to volume ratio for faster diffusion of oxygen in and out of the cell
• Lacks nucleus to store more haemoglobin for transportation of oxygen

Question 16

Structural features to function: root hair cell

Answer 16

Long and narrow root hair extension to increase surface area to volume ratio for faster osmosis of water molecules and diffusion of mineral salts in and out of cell

Question 17

Structural features to function: xylem

Answer 17

• Long hollow and continuous tubes without cross-walls to transport water with no obstructions
• Walls thickened with lignin to provide structural/mechanical support and prevents collapse of the vessel during transport of water