1.2 Ultrastructure of cells

Question 1

What are prokaryotic cells?

Answer 1

It is a cell with…
-no nucleus
-no organelles
-no compartmentalisation

Question 2

What are eukaryotic cells?

Answer 2

A cell that contains a nucleus.

Question 3

What is the structure and function of ribosomes?

Answer 3

-found in pro&eukaryotes
S: have two subunits made of RNA and protein
F: synthesize polypeptides (proteins) in a process called translation.

Question 4

What is the structure and function of the cytoskeleton?

Answer 4

-found in pro&eukaryotes
S: scaffolding in the cytoplasm.
F: provides internal structure and helps intracellular transport.

Question 5

What is the structure and function of the plasma membrane?

Answer 5

-found in pro&eukaryotes
S: phospholipid bilayer with proteins
F: semi-permeable—>selective barrier surrounding the cell

Question 6

What is the structure and function of a nucleus?

Answer 6

S: double membrane, spherical w/ pores
F: stores chromosomes which are made of DNA.

Question 7

What is the structure and function of a nucleolus?

Answer 7

S: found in the nucleus, no membrane, is granular, and dark
F: assembles ribosomes

Question 8

What is the structure and function of the rough ER?

Answer 8

S: ribosomes attached to cisternae (folds)
F: synthesizes proteins

Question 9

What is the structure and function of the smooth ER?

Answer 9

S: enzymes attached to its cisternae (folds)
F: synthesizes lipids like phospholipids and cholesterol

Question 10

What is the structure and function of the golgi apparatus?

Answer 10

S: vesicles and membranes near the plasma membrane
F: sorts, stores, modification, exports secretory products

Question 11

What is the structure and function of the mitochondrion?

Answer 11

S: double membrane, inner membrane folded
F: site of aerobic respiration, ATP production

Question 12

What is the structure and function of the chloroplast?

Answer 12

plant cells only
S: double membrane with discs
F: site of photosynthesis

Question 13

What is the structure and function of the vacuole?

Answer 13

plant cells only
S: large, central, fluid filled, 1 membrane
F: maintains hydrostatic (fluid) pressure

Question 14

What is the structure and function of the cell wall?

Answer 14

plant cells only
S: external cellulose cover
F: support and strength, prevents excess water uptake

Question 15

What is the structure and function of the lysosome?

Answer 15

animal cells only
S: sacs filled with hydrolysis enzymes
F: breakdown/hydrolysis of macromolecules

Question 16

What inferences can we make about the multitude of a certain organelle?

Answer 16

For example
-many mitochondria = energy consuming processes –> neurons/muscle cells
-extensive ER networks = secretory activity –> plasma/exocrine gland cells

Question 17

What’s the difference between a light microscope and an electron microscope?

Answer 17

Electron microscopes have a higher resolution and range of magnification, but cannot display in natural colors.

Question 18

What is the difference between the cell wall and the plasma membrane?

Answer 18

The cell well is made of cellulose surrounding a plant cell. A plasma membrane is found in both plant and animal cells.

Question 19

State one advantage a cell gains from being compartmentalized and having organelles.

Answer 19

Different chemical process can occur simultaneously in different parts of the cell.