Organelles

Question 1

What is an organelle?

Answer 1

A membrane bound structure that carries out a specific function for the cell

Question 2

How big is a nucleus roughly?

Answer 2

2 - 10 um

Question 3

What are 4 features of the nucleus?

Answer 3

It contains the genome of the organism
It has a double layer membrane with pores for mRNA movement
Contains a nucleolus - production of ribosomal RNA to form ribosomes
The shape is maintained by the nuclear matrix

Question 4

What are 6 features of the endoplasmic reticulum:

Answer 4

1. It is a highly folded membrane
2. RER is studded with ribosomes to process proteins
3. Proteins are chemically modified within the ER (internal lumen)
4. SER has few ribosomes, instead has transmembrane proteins for lipid/carb production
5. Main site of new membrane synthesis within the cell
6. Isolates calcium within the lumen

Question 5

Give 3 features of the Golgi apparatus:

Answer 5

1. It is a system of membrane sacs that works closely with the ER
2. Proteins are modified
3. Proteins are packaged into vesicles

Question 6

What is a vesicle?

Answer 6

A vesicle contains digestive enzymes which then matures into a lysosome when fused with the Golgi

Question 7

What is a lysosome?

Answer 7

A membrane-bound vesicle of digestive hydrolytic enzymes

Question 8

What do lysosomes do?

Answer 8

Digest incoming material or internal material

Question 9

What organisms are lysomes found in?

Answer 9

Animals, fungi, protist cells - rare in plants

Question 10

Give 5 features of a mitochondria:

Answer 10

1. Very small 1-4 um
2. 2 membranes with inner cristae to increase SA
3. Very vast amounts present in cells
4. Inner membrane is embedded with metabolic proteins
5. Mitochondria have their own genome

Question 11

What is a plastid?

Answer 11

Found only in plant and algae, a chloroplast is a plastid

Question 12

What are the features of a plastid? (5)

Answer 12

1. Larger than mitochondria
2. Double membrane at border, inner stroma space, thylakoids and grana present
3. Chloroplasts contain chlorophyll
4. Other plastids lack chlorophyll and used for storage
5. Plastids have a distinct genome

Question 13

What do mitochondria and chloroplasts have in common?

Answer 13

The endosymbiont theory - evolutionary relationships

Question 14

What are the 5 features of a vacuole?

Answer 14

1. Takes up 90% of space in plant cells
2. Serves as a storage area
3. Bound by tonoplast membrane with protein pumps
4. Plant cells provide high turgor pressure which provides strength
5. Animal cells don’t usually contain vacuoles

Question 15

What is a ribosome?

Answer 15

Small dense granules for protein synthesis

Question 16

What its a centriole?

Answer 16

Found in animal cells, creates the spindle in cell division

Question 17

What is a cytoskeleton?

Answer 17

Provides a cell framework - made out of proteinaceous microtubules, microfilaments and intermediate filaments