Module 1 - Cells

Question 1

What is meant by the term tonicity?

a) The tone / turgor of a solution relative to intracellular content
b) The osmolality of a solution relative to intracellular content
c) The osmolality of a solution relative to plasma
d) The osmolality of a solution relative to normal saline
e) The tone / turgor of a solution relative to plasma

Answer 1

c) The osmolality of a solution relative to plasma

Question 2

Where is energy used in cellular processes primarily stored?

a) Organic residues
b) High energy phosphate compounds
c) Na / K ATPase
d) Adenosine containing compounds
e) Energy rich hydrogen bonds

Answer 2

b) High energy phosphate compounds

Question 3

What is the inheritance pattern of mitochondria?

a) Recessive
b) Fraternal
c) Dominant
d) Maternal
e) 50% maternal, 50% fraternal

Answer 3

d) Maternal

Question 4

Membranes are formed from phospholipids. What is the structure of phospholipids? a) Hydrophobic head and fatty acid chains that are hydrophilic

b) Polar hydrophilic head and fatty acid chains that are hydrophilic
c) Polar hydrophilic fatty acid head and hydrophobic chains
d) Polar hydrophilic head and fatty acid chains that are hydrophobic
e) Hydrophobic head and fatty acid chains that are hydrophobic

Answer 4

d) Polar hydrophilic head and fatty acid chains that are hydrophobic

Question 5

What type of transporter is GLUT4?

a) Counter-transporter
b) Ion transporter
c) Uniporter
d) Co-transporter
e) Passive transporter

Answer 5

c) Uniporter

Question 6

The following are organelles found in human cells.

A: Mitochondria

B: Lysosome

C: Golgi apparatus

D: Rough endoplasmic reticulum

E: Smooth endoplasmic reticulum

F: Centrioles

Which participates in:

a) Oxidative phosphorylation
b) Cellular division

Answer 6

A: Mitochondria

F: Centrioles

Question 7

What is the freezing point of normal human plasma?

a) 0 degrees C
b) -0.54 degrees C
c) 0.5 degrees C
d) -1 degrees C
e) 1 degree C

Answer 7

b) -0.54 degrees C

Question 8

What is oxidation?

a) The gain of electrons
b) The loss of oxygen
c) The loss of hydrogen
d) The exchanged of oxygen for electrons
e) The exchange of hydrogen for electrons

Answer 8

c) The loss of hydrogen

Question 9

What is the principle process by which ATP is formed in the body?

a) Reductive phosphorylation
b) Organic phosphorylation
c) Redox phosphorylation
d) Oxidative phosphorylation
e) Glycophosphorylation

Answer 9

d) Oxidative phosphorylation

Question 10

The cell membrane is composed of a phospholipid bilayer, each layer comprising a head and a tail. Describe the properties of the head and tail, with regards to water solubility.

a) Head is polar, hydrophilic. Tail is nonpolar, hydrophobic
b) Head is non polar, hydrophobic. Tail is nonpolar, hydrophobic
c) Head is non polar, hydrophobic. Tail is polar, hydrophilic
d) Head is polar, hydrophilic. Tail is polar, hydrophilic
e) Head is non polar, hydrophobic. Tail is hydroneutral

Answer 10

a) Head is polar, hydrophilic. Tail is nonpolar, hydrophobic

Question 11

Which of the following is a function of mitochondria?

a) Formation of oxygen
b) Regulation of apoptosis
c) Storage of enzymes
d) Formation of mRNA
e) Utilisation of energy

Answer 11

b) Regulation of apoptosis

Question 12

Which of the following intercellular junctions attach cells to their basal laminas?

a) Gap junction
b) Tight junction
c) Desmosome
d) Hemidesmosome
e) Zonula adherens

Answer 12

d) Hemidesmosome

Question 13

What is the structural difference between granular endoplasmic reticulum and smooth endoplasmic reticulum?

a) Granular ER is decorated with ribosomes
b) Smooth ER is decorated with ribosomes
c) Granular ER is decorated with lysosomes
d) Smooth ER is decorated with lysosomes
e) Smooth ER contains an ATP-dependent Ca pump

Answer 13

a) Granular ER is decorated with ribosomes

Question 14

The Gibbs-Donnan equilibrium helps to explain the tendency of cells to swell. What prevents cellular swelling caused by the presence of impermeant intracellular anions?

a) Osmosis
b) The sodium pump
c) Reactive oxygen species
d) Glutathionylation
e) Passive flux

Answer 14

b) The sodium pump

Question 15

Which ion transporter is involved in the maintenance of the resting membrane potential?

a) Na, Ca antiporter
b) Na / Glucose transporter
c) Na, K ATPase
d) ENaC
e) RomK

Answer 15

c) Na, K ATPase

Question 16

Which of the following terms describes communication in which products of cells diffuse in the extracellular fluid to affect neighbouring cells?

a) Paracrine
b) Autocrine
c) Endocrine
d) Neural
e) Juxtacrine

Answer 16

a) Paracrine

Question 17

Chemical messengers commonly act by 4 different general mechanisms

A: Membrane receptor coupled to an ion channel

B: Membrane receptor coupled to G-proteins

C: Membrane receptor coupled to an enzyme

D: Cytoplasmic or nuclear receptors, which activate gene transcription

Match the above mechanism with it corresponding example

a) Thyroid hormones
b) Acetylcholine at the neuromuscular junction
c) Angiotensin

Answer 17

a) D: Cytoplasmic or nuclear receptors, which activate gene transcription
b) A: Membrane receptor coupled to an ion channel
c) B: Membrane receptor coupled to G-proteins

Question 18

What is the potassium concentration inside and outside the cell?

Answer 18

Potassium concentration inside the cell: 150mmol

Potassium concentration outside the cell: 5mmol

Question 19

What does the Na-K pump transport?

Answer 19

Three sodium ions outside for every two potassium ions inside

On ATP molecule split to acheive this

Question 20

What ions is the cell membrane usually permeable to at rest?

Answer 20

Potassium and Chloride

Question 21

What are the main intracellular and extracellular anions?

Answer 21

Main intracellular anions are proteins

Main extracellular anion is chloride

Question 22

What does the Nernst equation calculate?

Answer 22

It calculates the potential difference that an ion would produce if the membrane was permeable to this ion

Question 23

Nernst Equation formula

Answer 23

Question 24

What does the Goldman-Hodgkin-Katz form of the Nernst equation do?

Answer 24

It is expanded to take into acount multiple ions, multiplied by their permeability, to calculate the resting membrane potential across a semi-permeable membrane

Question 25

What are the two mechanisms for removing calcium from the cell?

Answer 25

1. Active transport via membrane bound pump activated by calmodulin using 1 ATP for each ion transported
2. Co-transport utilising sodium ions moving down the concentration gradient