Brainscape's Knowledge GenomeTM

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


See full index

Life 102 Biochemistry and biomedical sciences > Alan Boyd > Flashcards

Alan Boyd Flashcards

1
Q

What are macronutrients?

A

They are sources of energy

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

How much energy can carbohydrate and protein provide?

A

approximately 4 kcal per kg

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

How much energy can fat provide?

A

approx 9 kcal per kg (more energy dense)

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

What does C18:1 Δ9 denote?

A

it denotes an 18 carbon molecule with a single double bond at the 9 position

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

Below their melting point, how are triacylglycerols stabilised in solid form?

A

they are stabilised by van der Waals interactions between the acyl chains

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

The presence of unsaturated fatty acids in a triacylglycerol reduces the degree of molecular packing that is possible in the solid form so that………………. energy is required for melting

A

less

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

How can oils be converted into fats?

A

by adding a hydrogen across double bonds in the acyl chains. This process is called hydrogenation and requires a nickel catalyst.

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

In what configuration do you find the double bonds in naturally occurring unsaturated fatty acids?

A

cis configuration

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

Ture/False: in industrial hydrogenation, it is possible for trans double bonds to occur.

A

true

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

The consumption for trans fatty acids leads to an increased risk of…..

A

cardiovascular disease

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

Which country introduced a complete ban of trans fatty acids in 2003?

A

Denmark

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

What is the most expensive single class of drugs that are prescribed in the UK?

A

lipid regulating drugs, predominantly statins

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

Cholesterol is a precursor for biosynthesis of

A

steroid hormones

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

What do statins do?

A

reduce endogenous biosynthesis

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

Other than statins, what other approach is used to treat high cholesterol levels?

A

the use of a nutriceutical (plant stanol esters)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Other than statins, what other approach is used to treat high cholesterol levels?

A

the use of a nutriceutical (plant stanol esters) which are the active ingredient in the Benecol range of foods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where does most digestion and all absorption of nutrients take place in?

A

the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are enterocytes?

A

the predominant cells in the small intestinal mucosa (epithelial cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Enterocytes are linked together by what kind of junction?

A

tight

20
Q

In order to get from the gut lumen into the bloodstream, what do nutrients need to do to pass through the enterocytes?

A

They get taken up at the apical surface and leave through the basolateral surface

21
Q

Enzymes such as sucrases are often referred to as …………….. and include many digestive peptidases and …………………

A

brush-border enzymes; glycosidases

22
Q

Monoacylglycerols and fatty acids are able to diffuse through the lipid bilayer of the apical membrane and once inside the enterocyte they are?

A

reconverted into triacylglycerols and packaged into lipoproteins called chylomicrons.

23
Q

Chylomicrons are released into…

A

the lymph from where they eventually pass into the bloodstream

24
Q

Cholesterol binds to which transporter which explains how plant stanols are able to block uptake of dietary cholesterol?

A

NPC1L1

25
Q

How is the stanol concentration in the gut maintained?

A

plant stanols has a specific transporter to pump the stanols back across the apical membrane.

26
Q

How was the role of the specific cholesterol transporter discovered?

A

was discovered as a result of a compound called ezetimibe which was intially found to lowernserum cholesterol without any effect upon endogenous synthesis.

27
Q

Give examples of macronutrients

A

carbohydrates, fats, proteins

28
Q

Give examples of micronutrients

A

vitamins, essential fatty acids, minerals

29
Q

If starch is branched, what is it called?

A

amylose

30
Q

If starch is unbranched, what is it called?

A

amylopectin

31
Q

Glycogen resembles amylopectin but is it more or less branched?

A

more branched

32
Q

What is cellulose?

A

the primary constituent of plant cell walls, consists of glucose in long, unbranched chains in which the glucose monomers are linked by β-1,4 linkages

33
Q

What are hemicelluloses?

A

These are the main constituent of cereal fibres and are branched structures composed of pentoses and hexoses and the uronic acids. Hemicelluloses may be soluble or insoluble.

34
Q

What are pectins?

A

These are insoluble complex polysaccharides

35
Q

What are Gums?

A

these are soluble complex polysaccharides

36
Q

What are lignins?

A

these are non-polysaccahride woody polymers of aromatic alcohols.

37
Q

How many amino acids does myoglobin have?

A

153

38
Q

Is there a β structure in myoglobin?

A

no

39
Q

In myoglobin, how many helices are there and how are they ‘numbered’?

A

8, ‘numbered’ A-H

40
Q

What is Haem?

A

a tetrapyrrole ring structure (a porphyrin ring) with a central iron atom in the Fe(II) state.

41
Q

In haem, how many ligands can bind to the iron atom?

A

6

42
Q

Myoglobin exhibits a simple saturation curve for oxygen binding. This type of curve is referred to as a:

A

rectangular hyperbola

43
Q

The K(D[subscript]) of myoglobin for O2 is

A

2-3 mm Hg

44
Q

What is the difference between myoglobin and haemoglobin?

A

Myoglobin is an iron- and oxygen-binding protein found in the muscle tissue of vertebrates in general and in almost all mammals. It is related to hemoglobin, which is the iron- and oxygen-binding protein in blood, specifically in the red blood cells.

45
Q

What is the Adair equation?

A

it models the behaviour of a tetrameric binding protein exhibiting cooperative behaviour in terms of four sequential binding reactions.

Life 102 Biochemistry and biomedical sciences (4 decks)

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