Cell structure and function exam style questions

Question 1

If you get any of these answers wrong……

Answer 1

…..go and find out why!

Question 2

DNA adopts higher-level foldings, and wraps around: 1. ribosomes.

2. desmosomes.
3. histones.
4. lysosomes.
5. peroxisomes.

Answer 2

3. histones.

Question 3

Translation is the process of:

1. the movement of myosin on active filaments. 2. mRNA elongation.
2. DNA replication.
3. mRNA processing.
4. protein synthesis.

Answer 3

5. protein synthesis.

Question 4

For every glucose molecule broken down, glycolysis produces a net gain of:

1. two ATP and four NADH.
2. one ATP and two NADH.
3. four ATP and two NADH.
4. four ATP and four NADH.
5. two ATP and two NADH

Answer 4

5. two ATP and two NADH

Question 5

The Mitosis Promotion Factor (MPF) is formed when:

1. cyclin binds to CDK.
2. RAS-GTP phosphorylates cyclin.
3. CDK forms a complex with p21.
4. p21 binds to p53.
5. the nucleus breaks down.

Answer 5

1. cyclin binds to CDK (cycling dependent kinase complex).

Question 6

The key role of tRNA is in:

1. protein synthesis.
2. transcription.
3. replication.
4. cell division. 5. cell signalling.

Answer 6

1. protein synthesis.

Question 7

Which organelle adds and/or modifies carbohydrate on newly synthesised proteins?

1. proteasome
2. peroxisomes
3. endoplasmic reticulum 4. nucleus
4. Golgi body

Answer 7

5. Golgi body

Question 8

Cells of the pancreas will incorporate radioactively labelled amino acids into proteins. This “tagging” of newly synthesised proteins enables a researcher to track the location of these proteins in a cell. In this case, we are tracking an enzyme that is eventually secreted by pancreatic cells. Which of the following is the most likely pathway for movement of this protein in the cell?

1. From the nucleus to the ER to the Golgi.
2. From the ER to the Golgi to the nucleus.
3. From the Golgi to the ER to the nucleus.
4. From the ER to the Golgi and into vesicles that fuse with the plasma membrane.
5. From the ER to the lysosomes and into vesicles that fuse with the plasma membrane.

Answer 8

4. From the ER to the Golgi and into vesicles that fuse with the plasma membrane.

Question 9

Which of the following is correct about a codon?

1. It catalyses RNA synthesis.
2. It consists of discrete amino acid regions.
3. It consists of two nucleotides.
4. It may code for the same amino acid as another codon.
5. It may be edited using spliceosomes.

Answer 9

4. It may code for the same amino acid as another codon.

Question 10

Which process refers to the division of the cytoplasm into two daughter cells?

1. cytosol
2. mitosis
3. cytokinesis
4. meiosis
5. centrioles

Answer 10

3. cytokinesis

Question 11

Which of the following proteins is often mutated in cancer cells?

1. ras
2. actin
3. lamin
4. cyclin

Answer 11

1. ras

Question 12

Cancer cells have lost their control over the cell cycle. This generally involves:

1. ras protein being inactive.
2. multiple mutations.
3. p21 being up-regulated. 4. p53 being fully functional.

Answer 12

2. multiple mutations.

Question 13

Keratin:

1. forms the cortical network underneath the plasma membrane.
2. supports cell adhesion.
3. is a nuclear protein.
4. belongs to the microfilament protein family.

Answer 13

4. belongs to the microfilament protein family.

Question 14

What are enzymes called that control the activities of other proteins by phosphorylating them?

1. cyclins
2. ATPases
3. protein kinases
4. transferases

Answer 14

3. protein kinases

Question 15

According to the signal hypothesis, ribosomes are directed to the ER membrane by:

1. a signal-recognition particle that brings ribosomes to a receptor protein in the ER membrane.
2. moving through a specialised channel of the nucleus.
3. a specific characteristic of the ribosome itself, which distinguishes free ribosomes from bound ribosomes.
4. a chemical signal given off by the ER.

Answer 15

1. a signal-recognition particle that brings ribosomes to a receptor protein in the ER membrane.

Question 16

During which phase of the cell cycle do the chromatin fibres condense and shorten into chromosomes that are visible under the microscope?

1. telophase
2. prophase
3. anaphase
4. metaphase

Answer 16

2. prophase

Question 17

Cells manage to pack a lot of DNA into each nucleus. This is only possible because the DNA duplex is folded around a histone octomer to form a complex called a:

1. nucleosome.
2. desmosome.
3. lysosome.
4. ribosome.

Answer 17

1. nucleosome.

Question 18

In addition to ATP, what are the end products of glycolysis?

1. CO2 and NADH
2. H2O and Pyruvate
3. NADH, CO2 and pyruvate
4. CO2 and H2O

Answer 18

3. NADH, CO2 and pyruvate

Question 19

The alpha-helix and the beta-pleated sheet are both common forms found in which level of protein structure?

1. primary
2. tertiary
3. secondary
4. quaternary

Answer 19

3. secondary

Question 20

What are the hydrophobic parts of a phospholipid?

1. head group
2. neither head nor tail are hydrophobic
3. tail group
4. both head and tail are hydrophobic

Answer 20

3. tail group

Question 21

The functional units of DNA that contain the instructions for making one or
more proteins are:
1. chromosomes.
2. histones. 
3. codons. 
4. genes

Answer 21

4. genes

Question 22

Before the mRNA transcribed from a gene can be translated into a protein, it
must be:
1. edited to remove exons, and transported into the nucleus.
2. edited to remove exons, and transported into the cytoplasm.
3. edited to remove introns, and transported into the nucleus.
4. edited to remove introns, and transported into the cytoplasm.

Answer 22

4. edited to remove introns, and transported into the cytoplasm.

Question 23

Testosterone functions inside a cell by:
1. binding with a receptor protein that enters the nucleus and activates
specific genes.
2. acting as a signal receptor that activates ion- channel proteins.
3. becoming a second messenger that inhibits adenylyl cyclase.
4. acting as a steroid signal receptor that activates ion-channel proteins.

Answer 23

1. binding with a receptor protein that enters the nucleus and activates

Question 24

In eukaryotes there are several different types of RNA polymerase. Which type
is involved in transcription of mRNA for a globin protein?
1. RNA polymerase I
2. ligase
3. RNA polymerase II
4. RNA polymerase III

Answer 24

3. RNA polymerase II

Question 25

When a G protein becomes activated and causes an activation of enzymes: 1. ATP is consumed and cAMP is formed. 2. ATP is consumed. 3. cAMP is formed. 4. cAMP is broken down.

Answer 25

1. ATP is consumed and cAMP is formed.

Question 26

During mitosis, sister chromatids separate into daughter chromosomes during: 1. interphase. 2. telophase. 3. metaphase. 4. anaphase.

Answer 26

4. anaphase.

Question 27

Which of the following statements best describes proto-oncogenes? 1. They can code for proteins associated with cell growth. 2. They are produced by somatic mutations induced by carcinogenic substances. 3. Their normal function is to suppress tumor growth. 4. They are introduced to a cell initially by retroviruses.

Answer 27

1. They can code for proteins associated with cell growth.

Question 28

A cell is progressing through the cell cycle. The cell senses that there is a problem and it needs to initiate a break from progression to allow repairs to be undertaken. The class of protein that will initiate the break from progression is a/an: 1. oncogene. 2. mutated tumour suppressor protein. 3. proto-oncogene. 4. tumour suppressor protein.

Answer 28

4. tumour suppressor protein.

Question 29

If a signalling pathway includes a G protein coupled receptor that signals via phospholipase c, the most likely second messenger for this pathway will be: 1. IP3. 2. Na+. 3. ATP. 4. cAMP.

Answer 29

1. IP3.

Question 30

If a signalling pathway includes a G protein coupled receptor that signals via protein kinase A, the most likely second messenger for this pathway will be: 1. ATP. 2. IP3. 3. Na+. 4. cAMP.

Answer 30

4. cAMP.

Question 31

Is the following statement TRUE or FALSE? A phosphorylation cascade occurs where the activation of one kinase enzyme activates a second kinase enzyme which activates a third, and so on, and this continues on until the activated protein is able to achieve a cellular response. 1. It is false because the described process is called a phosphatase cascade. 2. It is true because but such a cascade is a short acting occurrence in the human body. 3. It is true because this allows redundancy of signalling to occur. 4. It is false because the aim of this process is to activate a protein, not to achieve a cellular response.

Answer 31

2. It is true because but such a cascade is a short acting occurrence in the human body.

Question 32

If a signalling molecule is able to form a hormone receptor complex in the cytoplasm of a cell, that signalling molecule must be: 1. able to cross the plasma membrane. 2. unable to cross the plasma membrane. 3. met at the cell surface by its receptor. 4. unable to initiate a signal transduction pathway.

Answer 32

1. able to cross the plasma membrane.

Question 33

Correctly complete the following sentence: The presence of ATP ________ the activity of the enzyme phosphofructokinase. 1. has no effect on 2. inhibits 3. stimulates 4. deactivates

Answer 33

2. inhibits

Question 34

Correctly complete the following statement: A researcher is characterising a protein that is part of a phosphorylation cascade within the cell. This means that she knows that the protein is translated by ______ ribosomes, and that this protein ______ be processed through the Golgi apparatus. 1. free; will not 2. attached; will 3. free; will 4. attached; will not

Answer 34

1. free; will not

Question 35

In the mitochondria, protons are pumped: 1. by the ATP synthase. 2. into the intermembrane space. 3. by using ATP. 4. into the matrix. 5. by acetyl CoA.

Answer 35

2. into the intermembrane space.