Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

WP 19 Biomed > Biochemistry > Flashcards

Biochemistry Flashcards

1
Q

How much energy is provided (kJ/g) in carbs, fats and protein?

A

Carbs - 16
Fats - 37
Protein 17

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the body’s greatest source of energy?

A

Carbs (45-65% of total energy).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the ratio of Na: glucose uptake with the Na/glucose co-transporter?

A

2 Na : 1 glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does glucose leave the epithelial cell (basolateral membrane)?

A

Facilitated diffusion through GLUT2 (transport protein) uniporter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens to glucose, galactose and fructose once they enter the bloodstream?

A

Galactose and fructose are converted to glucose in the liver.
In the liver, glucose is used to either make ATP or stored as glycogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are peptides absorbed in the small intestine?

A

The PepT1 peptide carrier can only transport tri- and Di-peptides which are further broken down into amino acids in the enterocyte.
Secondary active transport from the Na/K ATPase and the Na/H pump which makes protons leave the cell. The PepT1 transporter then pumps H ions and peptides in as co-transport.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the process of FFA and monoglycerides forming chylomicrons.

A

Once FFA and monoglycerides enter the enterocyte, they are reconverted to triglycerides and packaged into chylomicrons. They are incorporated into these lipoproteins together with apolipoprotein, cholesterol and phospholipids.
Chylomicrons are then released into central lacteals (lymphatic capillaries) by exocytosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define Vitamin and describe the differences between a vitamin and a mineral.

A

Vitamin -> A group of organic substances that are needed in small doses for normal cell function, growth and development.
Vitamins are made by living things, minerals found in the earth.
Vitamins are complicated organic substances while minerals are simple, inorganic substances.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a coenzyme?

A

Small organic molecules that temporarily bind to enzymes and whose presence is essential for biological activity of those enzymes.
Vitamins serve as coenzymes or precursors to coenzymes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the features of Fe deficiency?

A

Anaemia - can’t produce enough Hb in RBCs.

Fatigue, low energy levels, dyspnoea on exertion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the features of Vitamin A deficiency?

A

Normally liver stores 80-90% of Vitamin A, releasing it into circulation bound to pre-albumin and retinol-binding protein.
Deficiency impairs immunity and haematopoiesis, causing rashes and ocular effects.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the fat soluble vitamins? How are they absorbed?

A

A, D, E and K. Require lipids and bile salts in the diet in order to be absorbed, are carried by micelles and packaged into chylomicrons —> lymph —> blood.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the water soluble vitamins? Where are they absorbed?

A

B and C. Absorbed in the upper small intestine via diffusion directly into the blood. Similar to amino acids and monosaccharide transport. Exception is B12 which is a large charged molecule.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is B12 absorbed and distributed?

A

Binds to glycoproteins (intrinsic factor) released form parietal cells, forming a complex that resists digestion by GIT enzymes.
Vitamin B12-intrinsic factor complex is recognised by surface receptors by mucosal cells at the terminal ileum and is absorbed via endocytosis.
B12 is transported around the body via the protein, transcobalamin II and is stored in the liver.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the three disaccharides and what are they formed from?

A 
Sucrase = fructose + glucose. 
Maltase = glucose + glucose. 
Lactase = glucose + galactose.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where does protein digestion begin?

A

In the stomach where HCl denatures proteins and makes them lose their 3D shape.

17
Q

What are endopeptidases and what do they do?

A

Enzymes (trypsin, chymotrypsin and elastase) which cleave peptide bonds inside the polypeptide.

18
Q

What are exopeptidases and what do they do?

A

Enzymes (carboxypeptidase, aminopeptidase) which cleave peptide bonds on ends of polypeptides.

19
Q

What does the PepT1 transporter do and where is it located?

A

Transports di and tri peptides across the apical membrane with H+ ions. In the cell, these polypeptides are broken down into amino acids and exported via facilitated diffusion into the blood.
Located in the SI.

20
Q

What are the essential fatty acids?

A

Linoleic acid (omega-6 fatty acid) and alpha-linoleic (omega-3 fatty acid).

21
Q

What is the difference between a vitamin and a mineral?

A

Vitamins are organic, minerals are inorganic. Both are required for normal functioning of the body.
However, whereas all vitamins are required by the body, only some minerals are required for nutrition (Ca, Cu, I, Fe, Mg, P, K, S, Na, Zn).

22
Q

Describe coenzyme.

A

A small organic molecule that temporarily binds to enzymes and whose presence is essential for the biological activity of those enzymes.
Coenzymes belong to a larger group, called co-factors (small molecules required for the activity of associated ions).

23
Q

What are the consequences of Fe deficiency.

A

Without Fe, the body can’t produce enough Hb for RBCs —>anaemia

24
Q

What are the consequences of Vitamin B12 deficiency?

A

Psychiatric illness, thrombus formation, suppressed immune system, weakness, balance problems.

25
Q

What are the consequences of Vitamin A deficiency?

A

Impairs immunity and haematopoiesis and vision.

26
Q

What are the consequences of vitamin D deficiency?

A

Essential for bone, muscle growth and health. Vitamin C helps absorb Ca

27
Q

What are the consequences of Vitamin C deficiency?

A

Plays a role in collagen, carnitine, hormone and amino acid formation. It is essential for the immune system, for bone and blood vessel health and wound healing.

28
Q

How is Vitamin B12 transported around the body?

A

Bound to the protein, transcobalamin II.

29
Q

In what form is iron absorbed and by which transporter?

A

Iron is absorbed in its ferrous form (Fe2+) via the DMT1 transporter.

30
Q

Which protein stores iron in the cell, which protein exports iron out of the cell and which protein carries iron in the blood?

A

Ferritin: intracellular storage protein which can release Fe as needed.
Ferroportin: Fe export transporter which gets Fe2+ out of the cell to be oxidised to Fe3+.
Transferrin: serum protein which carries 2x Fe3+

WP 19 Biomed (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions