Biology

Question 1

Epithelium types

Answer 1

Simple: Stomach, intestines
Stratified:
Keratinised-Skin
Non-Keratinised-Oesophagus, Inside mouth

Question 2

Gastric Pit

Answer 2

Mucus layer: HCO3-
Mucous cell: Produce mucus
Parietal cell: Produce gastric acid

Question 3

Basolateral

Apical

Answer 3

Facing supporting tissue (bottom)

Facing lumen (top)

Question 4

Mucus

Answer 4

Network of proteins with sugar polymers attached.
Formation of viscous layer due to water retention.
Secretion of HCO3-

Question 5

Glycosylation

Answer 5

Post-translational modification of amino acid chain with sugar moieties.

Question 6

Protein sorting

Answer 6

Endoplasmic reticulum–>
Golgi apparatus–>
Transport vesicles–>
Membrane fusion.

Question 7

Gastric ulceration

Answer 7

1. Cell/tissue damage.
2. Histamine release, swelling, immune cells invade.
3. Increased blood flow.
4. Bleeding

Question 8

Membrane proteins

Answer 8

1. Integral (GPCR)
2. Lipid-modified: Lipid keeps protein associated with membrane.
3. Accessory: Bind to proteins in membrane.

Question 9

Solute transporter

Answer 9

Difference between ion channel: Ion must bind to transporter causing a conformational change.

Question 10

H. pylori

Answer 10

• Acid neutralising system; Urease enzyme
• Adhesion molecules; Binds to sugar molecules
• Movement; Flagella
• Degradation of mucus; Enzymes

Question 11

Urease enzyme

Answer 11

Proton gated urea transporter brings urea into membrane.
Broken down by urease.
Releases NH3
Ni2+ cofactor
-CO(NH2)2 + H20 --> 2NH3 + CO2
-2NH3 + 2H+ --> 2NH4+

Question 12

Urea breath test

Answer 12

• Patient takes C13 labelled urea

- If H. pylori present, urea broken down relesing labelled CO2

Question 13

Stool test

Answer 13

Antibody from lab coupled to enzyme that gives colour change.
Uses patient ANTIGEN

Question 14

Blood test

Answer 14

1. Patient sample added
2. Only antibody recognising H. pylori antigen binds
3. Enzyme linked antibody recognising human antibody binds.
4. Colour change

Uses patient ANTIBODY

Question 15

Therapeutic targets

Answer 15

Receptors-H2
Enzymes
Carbonic anhydrase (HCl secretion, Zn2+ active site)
Cox 1/Cox 2 attached to ER membrane
Transport proteins-Proton pump

Question 16

Cox

Answer 16

Cox 1
-Gastric protection, Renal function
-NSAID use gives undesirable effects
Cox 2
-Inflammatory response
-NSAID use targets this

Question 17

Epithellium

Answer 17

Epithelial cells: Simple, Stratified
Basement membrane: Acts as an anchor
Extracellular matrix: Collagen, Hyaluronan
Mast cell
Fibroblast

Question 18

Glycosylation

Answer 18

N-Glycosylation:
Asparagine
NH2 Group
O-Glycosylation:
Serine
OH Group

Question 19

Lipid Modified Membrane Proteins

Answer 19

N-myristoylation:
-N Terminus
-GLYCINE
-Amide
S-Palmitoylation:
-Near N-Terminus
-Serine/Cysteine
S-Prenylation:
-Near C Terminus
-Cysteine