Lecture 3: Cellular Organelles

Question 1

What is the function of the nucleus?

Answer 1

To contain genetic information and is the site of replication.

Question 2

What is the largest organelle in animal cells?

Answer 2

The nucleus.

Question 3

What is the special region in the nucleus where ribosomes begin to assemble from RNA and proteins?

Answer 3

The nucleolus.

Question 4

The content of the nucleus is known as what?

Answer 4

The nucleoplasm.

Question 5

The nuclear ___ is surrounded by two membranes and is perforated by thousands of nuclear ___ connecting the nucleoplasm with the cytoplasm.

Answer 5

Envelope, pores.

Question 6

Where does DNA replication and transcription into RNA occur?

Answer 6

In the nucleus.

Question 7

Where is RNA translated into polypeptides (proteins)?

Answer 7

The cytoplasm.

Question 8

What is the function of nuclear pores?

Answer 8

Regulate traffic (i.e. only small molecules and ions can pass through).

Question 9

In the nucleus, what does DNA and proteins form?

Answer 9

Chromatin.

Question 10

What is one molecule of DNA called and when is it visible?

Answer 10

A chromosome is visible during cell division.

Question 11

The nuclear envelope folds outward into the cytoplasm to form what?

Answer 11

The endoplasmic reticulum.

Question 12

These six organelles are part of which system?

1. Plasma membrane
2. Nuclear envelope
3. Endoplasmic reticulum
4. Golgi apparatus
5. Lysosomes
6. Vesicles

Answer 12

The endomembrane system.

Question 13

What organelle is associated with a network of interconnected membranes branching through the cytoplasm to form tubes and flattened sacs?

Answer 13

The endoplasmic reticulum.

Question 14

What is the interior compartment of the ER called?

Answer 14

The lumen.

Question 15

What increases the surface of the ER.

Answer 15

The folds.

Question 16

What are the two types of ER?

Answer 16

Rough and Smooth.

Question 17

What are the ‘little beads’ of the RER and what is there function?

Answer 17

Ribosomes are the location of protein synthesis.

Question 18

Where can proteins be chemically modified?

Answer 18

The rough endoplasmic reticulum.

Question 19

Where are membrane bound proteins made?

Answer 19

In the rough endoplasmic reticulum.

Question 20

Which type of ER doesn’t contain ribosomes and are more tubular than flattened sacs?

Answer 20

Smooth.

Question 21

Are the SER and the RER connected?

Answer 21

Yes.

Question 22

These four functions are associated with which organelle?

1. Chemical modification of toxic molecules
2. Site of glycogen degradation in animal cells
3. Site of lipid and steroid synthesis
4. Stores calcium ions to trigger cell responses.

Answer 22

The smooth endoplasmic reticulum.

Question 23

What organelle modifies, concentrates, packages and sorts proteins?

Answer 23

The Golgi apparatus.

Question 24

Which organelle adds carbohydrates to proteins?

Answer 24

The Golgi apparatus.

Question 25

What region of the GA is closest to the plasma membrane?

Answer 25

Trans region.

Question 26

What region of the GA is in between the cis and trans regions?

Answer 26

The medial region.

Question 27

What region of the GA is closest to the nucleus or an RER patch?

Answer 27

Cis region.

Question 28

What do the cis, medial and trans regions of the GA have that varies from each other?

Answer 28

Different enzymes and functions in different regions.

Question 29

What is the function of a lysosome?

Answer 29

The breakdown of foods, other cells and foreign bodies.

Question 30

What is the function of mitochondria?

Answer 30

Conversion of energy from food into ATP using molecular oxygen (CELLULAR RESPIRATION).

Question 31

What are the names of the membranes of the mitochondria?

Answer 31

The outer and inner membranes.

Question 32

Can mitochondria divide autonomously?

Answer 32

Yes.

Question 33

Which organelle is associated with the four following functions? 1. Storage of waste materials 2. Structure supporting plant due to water pressure (turgor) 3. Reproduction (i.e. pigments of plants to attract) 4. Digestion

Answer 33

Vacuoles.

Question 34

What do chloroplasts belong to?

Answer 34

Plastids.

Question 35

What is the function of the chloroplast?

Answer 35

Contain DNA and green pigment chlorophyll and are the site of photosynthesis.

Question 36

Why is the cytoskeleton not an organelle?

Answer 36

It is not membrane enclosed.

Question 37

Which organelle is associated with the following functions? 1. Support and maintain cell shape 2. Holds organelles in position within the cell 3. Moves organelles around the cell 4. Movement of the cytoplasm (cytoplasmic streaming) 5. Interaction with extracellular structures.

Answer 37

The cytoskeleton.

Question 38

What are the two functions of microfilaments and what are they composed of?

Answer 38

1. Help the cell or cell parts to move 2. Determine and stabilise cell shape - Composed of actin monomers (is a protein)

Question 39

What are the two structural functions of intermediate filaments?

Answer 39

1. Anchor cell structure in place 2. To resist tension

Question 40

What are the two functions of microtubules?

Answer 40

1. Form a rigid internal skeleton in some cells 2. Act as a framework along which motor proteins can move structures within the cell.

Question 41

Are microtubules and microfilaments quickly assembled and disassembled?

Answer 41

Yes.

Question 42

What role do microtubules have in cell division?

Answer 42

Distribution of chromosomes to daughter cells.

Question 43

What are cilia and flagella composed of?

Answer 43

Microtubules.