Lecture 5: Structure/Fctn of lipids and Lecture 6: Carbs Flashcards
1
Q
Fatty acids (FA)
A
Produce energy, synthesis of Triglycerides (TG), PL
2
Q
Triglycerides (TG)
A
Lipid/ fatty acid storage (unused calories)
- glycerol molecule + 3 fatty acids
- generated by esterification of fatty acids to glycerol
3
Q
Phospholipids are involved in
A
cell membranes, cell signaling
4
Q
Cholesterol
A
cell membranes, steroids, Vitamin D and bile acid synthesis
5
Q
Bile acids
A
Solubilize dietary fat and oil and help with their intestinal absorption
6
Q
Eicosanoids are involved in
A
Signaling, regulation of inflammation
7
Q
Sphingolipids
A
Both cell signaling and cell membrane stabilization and protection against harmful chemicals
8
Q
Saturated fats have
A
no double bond
more hydrogen atoms
more saturated- > higher melting point
9
Q
Unsaturated
A
one double bond
10
Q
Polyunsaturated
A
more than one double bond
11
Q
Fatty acids
A
- occur in the body mainly as esters (attached to a glycerol) like in phospholipids or triglycerides
- usually contain even number of carbon atoms when in natural fats
12
Q
cis form
A
120˚ is saturated and then becomes unsaturated where at the bond the angle becomes 120˚
13
Q
trans form
A
110˚ looks like regular saturated bond
ch3ch2ch2ch2ch2ch3
14
Q
Omega 3 Fatty acids
A
- Essential polyunsaturated fatty acids
- Present in fish oil, walnut oil, squid oil
15
Q
TG effects
A
- High levels of TG can lead to complications such as heart diseases, stroke, obesity and metabolic syndrome (diabetes).
- Treatment diet, exercise and some lipid lowering drugs (fenofibrate)
Normal level is less than 150 mg/dL
16
Q
Phospholipid
A
1 glycerol+ 1 phosphate group + 2 fatty acids
- amphiphilic
- play an important role in plasma membrane structure and function
17
Q
Phosphatidylethanolamine is composed of:
A.glycerol and 2 fatty acids.
B. Phosphatidic acid, 2 fatty acids and a polar head group.
C.glycerol and one fatty acid and a polar head group.
D.glycerol and 3 fatty acids.
A
B. Phosphatidic acid, 2 fatty acids and a polar head group
18
Q
Platelet activating factor (PAF)
A
PAF functions as a mediator of hypersensitivity, acute inflammatory reactions, and anaphylactic shock
19
Q
What kind of phospholipids will increase fluidity of the plasma membrane?
A.Those that are rich in polyunsaturated fatty acids.
B.Those that are rich in saturated fatty acids.
C.Those that have a hydrophilic polar group
A
A.Those that are rich in polyunsaturated fatty acids.
- having multiple bonds allows for there to be space in between the molecules. This allows passage of other things in those spaces which allows fluidity
20
Q
Fatty acid elongation
A
Fatty acid synthesis
-involves acyl-CoA and requires energy
21
Q
Fatty acid Beta oxidation
A
Fatty acid degradation
22
Q
Cholesterol
A
including triglycerides and phospholipids (major lipids of body)
- shuttled via lipoproteins in the body to different organs
- used to build cells and certain hormones
- involved in the synthesis of steroids, vitamins and bile acids
- too much can cause heart disease
23
Q
Which enzyme for statin drugs
A
HMG-CoA reductase
24
Q
What are Eicosanoids?
A
Eicosanoids are derived from arachidonic acid.
- They are involved in a number of functions regulating inflammation, immune response, cell growth, blood pressure.
- They can also cause fever and contribute to perception of pain.
25
Steroid example
Cortisol
| - type of cholesterol
26
Bile acids example
Lithocholic acid
| - type of cholesterol
27
Glucose is
stored as glycogen in liver and muscle
-important source of energy during cellular respiration
- major metabolic fuel in mammals
-
28
Glycogenesis
synthesis of glycogen. Involves hexokinase, phosphoglutamase
29
Monosaccharides
simple sugars
- most basic units of carbohydrates
formula CnH2nOn
- classified according to the number of carbons they contain in their backbone structures
30
Aldoses
- carbonyl group on the end
| - ex: glucose (C6H12O6), ribose (C5H10O5), glucofuranose
31
Ketoses
- carbonyl group on the inner portion of molecule
| - ex: fructose, ribulose
32
D-ribose
- nucleic acid and metabolic intermediate
| - structural component of nucleic acids and coenzymes including ATP
33
D- Ribulose
- metabolic intermediate
| - Intermediate in the pentose phosphate pathway
34
D-Xylose, D-Arabinose, D-mannose
constituent of glycoproteins
| - source is plant gums
35
D-Glucose
- found in fruit juices, hydrolysis of starch, cane or beet sugar, maltose and lactose
- the main metabolic fuel for tissues, "blood sugar"
36
D-Fructose
- found in fruit juices, honey, hydrolysis of cane or beet sugar and insulin
- readily metabolized either vis glucose or directly
37
D-galactose
- hydrolysis of lactose
- synthesized in mammary gland for synthesis of lactose in milk
- readily metabolized to glucose
38
Alpha conformation
You look at the two molecules next to oxygen. R-group and OH and they should facing opposite directions
39
Beta conformation
You look at the two molecules next to oxygen. R-group and OH and they should facing the same directions
- beta both
40
Cellulose
linear structure with many monosaccharides
41
During glycolysis, 1 molecule of glucose produces
2 molecules of pyruvate
42
Glucosamine
monosaccharide that contains a nitrogen atom
43
Glycosylation
- major form of protein modification
| - sugars are added in the golgi and ER
44
Glycoproteins
- contain one or more covalently linked carbohydrate chains
- cell signaling,
- plays a major role in cell recognition
- protect cell walls
- stabilize proteins against proteolysis
45
Sugars have
-large numbers of stereoisomers bc they contain several asymmetric carbon atoms
46
Hypertriglyceridemia
* Normal: Less than 150 mg/dL
* Borderline high: 150 to 199 mg/dL
* High: 200 to 499 mg/dL
* Very high: 500 mg/dL or above
47
Polar head groups are
hydrophilic
48
Apolar chaines are
hydrophobic
| - tails
49
Plasmalogens are
Enriched in myelin sheaths and protects against reactive
| oxygen species
50
Mutations in the ABCD1 gene lead to
impaired transport of
VLFAs to peroxisome for degradation. This leads to their accumulation in vulnerable tissues such as brain. This become toxic to myelin and result in demyelination of axons.
- The disease are called leukodystrophies
51
Cholesterol is involved in a number of biologically
| and physiologically important function such as
* Important component of the plasma membrane.
* Regulates membrane fluidity.
* Involved in biosynthesis of steroid hormones.
* Component of lipoproteins VLDL, LDL and HDL.
52
Lipoproteins
• Very low density lipoproteins (VLDL)
• Low density lipoproteins (LDL)
• High density lipoproteins (HDL) shuttles lipids to the
liver for catabolism
53
What is good cholesterol?
HDL cholesterol
| - happy cholesterol
54
What is bad cholesterol?
LDL cholesterol
| - lousy cholesterol
55
HDL Cholesterol
With HDL cholesterol the higher the better
- • <40 mg/dL for men and <50 mg/dL for women = higher risk
• 40-50 mg/dL for men and 50-60 mg/dL for women = normal values
• >60 mg/dL is associated with some level of protection against heart
disease
56
LDL Cholesterol
With LDL cholesterol the lower the better
• <100 mg/dL = optimal values
• 100 mg/dL-129 mg/dL = optimal to near optimal
• 130 mg/dL-159 mg/dL = borderline high risk
• 160 mg/dL-189 mg/dL = high risk
• 190 mg/dL and higher = very high risk
57
```
Which of the following enzymes is targeted by statins (cholesterol lowering drugs)?
A. HMG-CoA reductase.
B. Acetyl-transferase.
C. Fatty acyl transferase.
D. Glycogen phosphorylase.
```
A. HMG-CoA reductase
58
Total Serum Cholesterol:
* <200 mg/dL = desired values
* 200–239 mg/dL = borderline to high risk
* 240 mg/dL and above = high risk
59
Lipids are involved in the
synthesis of steroid hormones and eicosanoids
| prostaglandins leukotrienes and thromboxanes
60
Prostacyclin (PGI2) target
- endothelium
- kidney
- brain
61
Thromboxane A2 target
- platelets
- macrophages
- kidney
- smooth muscle
62
Prostaglandin E2 target
- brain
- kidney
- smooth muscle
63
Prostaglandin F2a target
- brain
- kidney
- smooth muscle
64
Diseases associated with carbohydrate metabolism
| include
- diabetes mellitus
- galactosemia
- glycogen storage diseases
- lactose intolerance
65
Trioses (C3H6O3)
- Glycerose
(glyceraldehyde)
- Dihydroxyacetone
66
Tetroses (C4H8O4)
Erythrose
| Erythrulose
67
Pentoses (C5H10O5)
Ribose
| Ribulose
68
Hexoses (C6H12O6)
Glucose
| Fructose
69
```
Glucose is:
A. an ester
B. a ketose
C.an aldose
D. an ether
```
C.an aldose
- has an aldehyde group on carbon 1
70
L-Xylulose
- Metabolic intermediate
-Excreted in the urine in
essential pentosuria
71
D-glucose and D-Fructose can exist in
alpha and beta conformation
72
```
Glucosamine is a naturally occurring amino sugar with the following structure. In humans it is the precursor for glycosaminoglycans, glycolipids and glycoproteins
What is its configuration?
A. Alpha-D
B. Alpha-L
C.Beta-D
D.Beta-L
```
A. Alpha-D
73
Starch molecule looks like
- polysaccharide
- simplest form is amylose: looped form
- amylopectin is the branched form: branches out
74
Glycogen molecule looks like
- polysaccharide compose of alot more subunits than starch
- branches out
- less ordered
75
Cellulose (fiber) looks like
- polysaccharide
| - very order structure
76
Glucose is stored as
glycogen in liver and muscle
77
Glycogenesis
synthesis of glycogen
78
Glycogenolysis
degradation of glycogen
79
1 Acetyl-CoA yields
1 ATP, 3 NADH and 1 FADH2
80
1 NADH yields
2.5 ATP
81
1 FADH2 yields
1.5 ATP
82
```
During glycolysis, 1 molecule
of glucose produces.
A. 1 molecule of pyruvate
B. 2 molecules of pyruvate
C. 3 molecules of pyruvate
```
B. 2 molecules of pyruvate
83
Glucosamine
monosaccharides that contain a nitrogen atom
84
Monosaccharides with amine groups are found
| mainly in
the carbohydrate chains of glycoproteins
85
All N-linked carbohydrates are linked through
N-Acetylglucosamine and the side chain of Asparagine
86
Most O-linked carbohydrate covalent attachments to proteins involve a linkage between
the monosaccharide N- Acetylgalactosamine and the
| side chain of a serine or threonine residue
