Metabolism Flashcards
(119 cards)
1
Q
Metabolism
A
The chemical processes that occur within a living organism in order to maintain life
2
Q
Digestion
A
The process of breaking down food to its smallest components so that it can be absorbed in the intestine
3
Q
Absorption
A
The transport of nutrients from the intestine into the blood or lymph system
4
Q
3 Carb Monosacchrides
A
Glucose
Fructose
Galactose
5
Q
3 Carb Disaccharides
A
Sucrose
Lactose
Maltose
6
Q
What is a oligosaccharide
A
3-10 sugar molecules
7
Q
2 Oligosaccharides
A
Raffinose
Stachyose
8
Q
What is a polysaccharide
A
10 or more sugar molecules
9
Q
2 Types of carb polysaccharides
A
Starch
Glycogen
10
Q
what 5 enzymes are involved in carb metabolism
A
Salivary Amylase
Pancreatic Amylase
Maltase
Sucrase
Lactase
11
Q
Where does carb digestion start
A
Mouth via Salivary Amylase
12
Q
What does salivary amylase do
A
Breakdown of polysaccharides to shorten sugar units
13
Q
Starch breakdown disaccaride and mono
A
Di: Maltose
Mono: Glucose
14
Q
Why is chewing important
A
Increases surface area for salivary amylase to contact with breaking down further
15
Q
Where does saliva come from? x3
A
Parotid Glands
Sublingual Glands
Submandibular glands
16
Q
What occurs to carbs at stomach
A
Amylase slows due to acidic enviroment
Chyme is expelled into duodennum
17
Q
What is chyme
A
The semifluid mass of partly digested food expelled by the stomach into the duodendum
18
Q
Where does majority of car absorption occur
A
Duodenum and the Jejunum
19
Q
What 3 enzymes are used to digest carbs in small intestine
A
Di to Mono
Lactase
Maltase
Sucrase
20
Q
Lactase is made of what
A
Glucose and Galactose
21
Q
Maltose is made of
A
2x glucose
22
Q
Sucrose is made of
A
Glucose + Frictose
23
Q
What occurs in carb digestion in small intetsine
A
Amylase is secreted into pancreatic juice breaches starches into smaller glucose units
Disaccharides and small polysaccharides are digested by specific enzymes located in the brush borders of the intestinal epithelial cells (then into blood)
24
Q
Transporter for brush borders of the intestinal epithelial cells for glucose and galactose
A
Glut 1
25
Enzyme for brush borders of the intestinal epithelial cells for fructose
Glut 5
26
Enzyme from epithelial cell into blood
Glut 2
27
What stimulates glucose uptake from food
Insulin (high blood sugar)
28
What stimulates glucagon from stores (glycogen breakdown)
Glucagon
29
What is glycogenolysis
Breakdown of glycogen to glucose by low blood sugar/glucagon
30
What is the alpha cells of the pancreas produce
Glucagon
31
What do the beta cells of the pancreas produce
Insulin
32
What is the hyperinsulinemic-euglycemic clamp
Gold standard method for measuring insulin sensitivity
-When glucose inflow is matched to insulin uptake from tissue so that blood glucose becomes stable
33
What is insulin sensitivity
How much of an increase in tissue blood glucose uptake occurs for a given concentration of blood insulin
34
What does insulin sensitivity increased mean
Rate of blood glucose removal from blood is increased at a given blood insulin concentration
35
What does decreased insulin sensitivity mean
Rate of glucose removal from blood is decreased at a given blood insulin concentrtion
36
How does a hyperinsulinemic-euglycemic clamp work
1)Infuse insulin to elevate blood insulin concentration
2)Infuse glucose to increase blood glucose concentration
When glucose inflow is matched to insulin uptake from tissue so that blood glucose becomes stable
Where the clamp happens tells us insulin sensitivity, greater tissue uptake per concentration insulin
37
What does the clamp tell us
When glucose inflow is matched to insulin uptake from tissue so that blood glucose becomes stable
Where the clamp happens tells us insulin sensitivity, greater tissue uptake per concentration insulin
38
Insulin clamp curve higher means
Higher insulin sensitivity
39
Type 1 Diabetes
Insulin deficiency as pancreatic beta cells are unable to produce insulin
40
Type 2 Diabetes
Insulin level is insufficient to compensate for insulin resistance resulting in hyperglycaemia
41
Pre-diabetes fasting glucose of HbA1C o what levels
6.0%-6.4%
42
What is glycated hemoglobin
Glucose in the bloodstream can bind to the protein Hb
43
What does gkycated heme tell us
Diagnosis of diabtes
-Average plasma glucose over previous 2-3 months (higher percentage = decrease inckusin resiatnce = higher blood glucose)
44
Healthy HbA1C
5.5%-5.7%
45
Diabetic HbA1C
greater the 6.5%
46
What enzyme is used to bring glucose into muscle cell from blood
glut 4
47
Glucose is used by skelteal muscle how
Undergo Glycoysis to form pyruvate
-to make ATP by TCA
48
Where is the ETC and TCA cycle occur in the cell
Mito
49
What is the structure of the mito
Outer Mito Mem
Intermembrane space
Innermito (etc) (CRISTAE)
Matirc
50
Subsarolecmmal mito fractions do what
Active Transport
51
Intermyofibrillar mito fractions do what
Contractile
52
Cristae (therefore ETC) increase with what
Exercise training (more atp)
53
What is important about the TCA cycle
Pyruvate is used to create NADH and FADH2
54
What are NADH and FADH2 used for?
Electron carriers and electron donars for etc
55
What complexs in ETC create gradient
1,3,4
56
What does complex 1 do
NADH + H+ gradient
57
What does complex 2
FADH2
58
Wjay complex involves oxygen that the H+ will come back to in rte membtane from intermembtane space
Complex 4
59
Explain gradient in ETC
H+ from matrix into intermembrane
Oxygen brings back in ATP synthase
60
What occurs to undigested carbs
Celluose (fibre of the form diet carb)
-Celluolose is resistant to digestive enzymes and is either
1)Excreted in feces
2)Fermented bt bacteria in large intestine
61
What pushes undigested carbs to colon
Peristaltic movemets
62
Peptide bonds break via what
Hydrolysis
63
Peptide bonds form via what
Condensation
64
The peptide bond of a protein is formed between what
Carboxyl group and amino group
65
What are the 5 enzymes involved in protien/aa metabolism
Pepsin
Trypsin
Chymotrypsin
Carnpxypeptidase
Elastase
66
Where does the chemical digestion of protein start
Stomach
67
What secretes HCL
Parietal cells in the stomach
68
What secretes Pepsinogen
Chief Cells in the Stomach
69
What is the role of Gastrin
Secreted by the stomach to increase HCL and pepsnogen instomach
70
What is pepsinogen
Inactive form of pepso activated by HCL (decreasing pH)
71
What does pepsin do
Converts proteins into smaller polypeptides
72
What free indvidual amino acids x3
Pancreatic Proteases
Brush Border Enzymes
Peptidases
ALL BEFORE SMALL INTESTINE
73
What hydrolysis peptide bonds (breaks down)
Pancreatic Proteases
74
What are the 4 Pancreatic Proteases
1. Trypsin
2.Chymotrypsin
3. Carboxypeptidase
4. Elastase
75
What is the central hub for AA metabolism
Liver
76
Where does most absorption of AA occur
Small Intestine
77
From Small Intestine where do AA go
Blood then to hepatic portal vein to liver
78
What are the 3 things that occur to AA in liver
1)Protein Synthesis
2)Transamination
3)Oxidation
79
What are transamination reactions
Transfer of the amino group from one amino acid to va keto acid via amino transferase enzymes
80
Why may transamination reaction be important
Produce pyruate for energy
81
What impacts circulating AA levels
First-pass splanchnic extraction
82
What is First-pass splanchnic extraction
The uptake and utilization of AA by the GI tract and liver to support protein turnover and metabolic processes
MOST IMPORTANT TO LIFE
83
What percentage of total AA are available in system circulation ?
55%
84
What percentage of total AA are absorbed into skeletal muscle?
20%
85
What percentage of total AA are used for MPS?
11%
86
Where is branched-chain AA metabolism primarily initiated?
Skeletal Muscle
87
What are the 3 branched chained AA
Isoleucine
Leucine
Valine
88
What enzymes bring in BCAA into muscle cell x2
LAT-1- LEUCINE
SNAT-2
89
What two enzymes metabolize BCAA once inside cell?
BCAT- Transanimation
BCKD - Oxidative Decarboxylation
90
BCAT is used for what
Transanimation
91
BCKD is used for what
Oxidative Decarboxylation
92
T or F BCAA bypass metabolism in splenic tissues
TRUE
93
What is a deamination reaction
Amino group is removed from the aa producing Ammonia.
Ammonia is a toxic by-product which needs to undergo conversion to ammonium before urea cycle
94
Glutamate dehydrogenase does what
deamination reaction enzyme
95
Why may a deamination reaction be imprortant
Alpha-ketogluterate for TCS
96
Prior to urea cycle ammonia turns into what
Ammonium
97
What are two ways BCAA metabolism impacts metabolic pathways
Transanimation produces pyruvate
Deanimation produces alpha-ketogluterate
which are byproducts for TCA cycle
ENERGY
98
Where does the urea cycle take place
Liver
Processes nitrogenous products and houses urea cycle
Then urea is excreted in the kidneys
99
How is the large intestine a side of AA metabolism
Remnant undugested and unabsorbed components of dietary proteins travel to large intestine where they are metabolized by microbacteria or digested by remaining proteases or peptidases
100
2 Key enzymes in fatty acid metabolism
Lingual Lipase
Pancreatic Lipase
101
Short chain FA
C4-C6
102
Med Chain FA
C8-C10
103
Long Chain FA
C12-C14
104
Where does fat digestion begin
Mouth
105
What is the role of lingual lipase?
Enzyme splits triglycerides into fatty acids and glycerol in mouth
Lingual Lipase is in saliva
106
What occurs in the stomach for digestions of Fat
Lipase continues to breakdown triglyerides in stomach but slows
107
What contributes to digestion of fat in duodenum?
Chym enters bile salys and pancreatic lipase are secreted into duodenum
Bile salts emusify large lipid dropelts into small ones
Pancreatic lipase breaks down into
FA
Diacylgkyceros
monoacylgkycerons
Micelles transport fatty acid to villi where contents of tehe micelle enter epithelial cell
108
What 2 enzymes are used in duodenmum for fat
Bile Salts
Pancreatic Lipase
109
What are miscelles
Circular/disk shaped structures comorised of compounds like phospholipids and fatty acids
Carry FA to eputhelial cells
110
What happens to short and med chained fatty acids in ep cells
go into blood
Bind to albumin
Transported to liver
111
What happens to long chained fatty acids in ep cells
Re-esterfied to triglycerides which combine with cholesterol and phosopholipids to produce chylormicrons
112
What are chylomicrons used for/ where are they circulated
It allows the transport of long-chain FS in plasma but is absorbed by the lymph system prior to transport in the circulatory system
113
What happens to chylomicrons when they arrive at skeletal muscle
Lipoprotein lipase (LPL) breaks down triglcerides into free fatty acids and glycerol
Transported into cell through transporters on membrane FABPpm and CD36
114
Fat Skeletal Muscle transporters x2
FABPpm and CD36
115
T or F only long chained FA need transprorters into skeletal muscle
True
116
What is beta-oxidation
Reduction of a long chained FA to produce acetyl-coa for energy in TCA
117
What is the rate limiting steo in long chain fatty acid oxidation
CPT1
Carnitine transferase
118
Explain Beta Oxidation
Long chain fatty acid is converted to fatty acyl-coa(Palmitolyl-CoA)
Cartnitine is added to palmitoyl coa by CPTI to allow palmitoyl coa to go through membrane
CPII removes cartitine and palmitoyl-coa/acetyl-coa can be used to produce acetyl-coa
119
Once thru membrane bet-oxudation does what
Generate acetyl-coa by removing 2 carbons from fatty acid chain
Also generates FADH2 and NADH
