1.2 Ultrastructure of Cells

Question 1

Label the bacterium.

Answer 1

A. Villi

B. Flagellum

C. Nuclear area (nucleoid) containing DNA

D. Plasmid

E. Ribosome

F. Cytoplasm

G. Plasma Membrane

H. Cell wall

I. CapsuleNext

Question 2

Differentiate between prokaryotic and eukaryotic ribosomes, nuclei, mitochondrion presence, compartmentalization (organelle presence and membranes).

Answer 2

Prokaryote: Eukaryote

• 70S (small) ribosomes: 80S (large) ribosomes
• Nucleoid containing DNA: True nucleus containing DNA
• No mitochondria: Mitochondria
• Cell parts: Organelles
• No internal membranes: Internal membranes enclose organelles

Question 3

What are a few advantages of eukarytotic compartmentalization?

Answer 3

• Enzymes and substrates for a certain process can be more concentrated than if spread across the cytoplasm
• pH balance for a specific chemical process can be more easily maintained
• Substances that can cause cellular damage can be kept inside the membrane of an organelle

Question 4

What are the organelles of eukaryotic cells?

Answer 4

Nucleus, rER, Golgi Apparatus, Lysosomes, Mitochondrion, Free Ribosomes, Chloroplast, Vacuoles, Microtubules, Cilia and Flagella.

Question 5

What is the function of the nucleus?

Answer 5

Contains chromosomes of DNA (chromatin). Replicates DNA.

Question 6

What is the function of the rER?

Answer 6

Synthesizes proteins to be carried to the golgi apparatus. Made of cisternae. Ribosomes present.

Question 7

What is the function of the Golgi Apparatus?

Answer 7

Made of cisternae. No ribosomes. Many vesicles. Processes proteins from the rER to be sent out of the cell.

Question 8

What is the function of lysosomes?

Answer 8

Formed by golgi vesicles? Break down ingested food in vesicles or break down defective vesicels.

Question 9

What is the functionof mitochondrion?

Answer 9

Produce ATP for aerobic cellular respiration. Fat digestion.

Question 10

Function of free ribosomes?

Answer 10

Synthesize proteins, release them into cytoplasm. Formed in nucleolus.

Question 11

Function of chloroplast?

Answer 11

Filled with thylakoids. Produce glucose and other compounds by photosynthesis.

Question 12

Function of vacuoles?

Answer 12

Plant cells have large vacuoles making up the majority of the cell. Animal cells absorb food and digest them in vacuoles. Unicellular organisms use vacuoles to transport materials in the cells?

Question 13

Function of vesicles?

Answer 13

Transport of materials within the cell

Question 14

Function of microtubules and centrioles?

Answer 14

Microtubules move chromosomes during cell division. Animal cells have centrioles which form anchor point for microtubules during cell division.

Question 15

Function of cilia and flagella?

Answer 15

Whiplike structures projecting from cell surface. Flagella usually larger and only one is usually present and is used for movement. Cilia help control fluid currents.