Exam 2 Flashcards
(187 cards)
1
Q
Three pentose sugars
A
ribose
deoxyribose
ribitol
2
Q
What is special about sugar alcohols (structure)
A
two alcohol groups
3
Q
what is special about sugar alcohols (metabolism)
A
low calorie
4
Q
three dietary monosaccarides
A
glucose
galactose
fructose
5
Q
beta anomers have this
A
OH on the same side of the ring
6
Q
alpha anomers have OH group in this position
A
down (axial)
7
Q
beta anomers have OH group in this position
A
up (equitorial)
8
Q
OH group of this mono is on the right side of the stick drawing
A
glucose
9
Q
OH group of this mono is on the left side of the stick drawing
A
galactose
10
Q
The aldehyde group of this mono is on the second carbon
A
fructose
11
Q
This is formed between the hemiacetal group of a saccharide and the hydroxyl group of the same compount
A
glycosidic linkage
12
Q
a substance containing a glycosidic bon is this
A
glycoside
13
Q
This Di has an alpha 1-4 glycosidic bon
A
maltose
14
Q
this di has a beta 1-4 glycosidic bond
A
lactose
15
Q
this di has an alpha 1-2 glycosidic bond
A
sucrose
16
Q
this di is found in fungi and plants
A
trehalose
17
Q
glucose bound to galactose
A
lactose
18
Q
glucose bound to fructose
A
sucrose
19
Q
glucose bound to glucose
A
maltose and trehalose
20
Q
when a sugar has an open chain form with an aldehyde group it is classified as this
A
reducing sugar
21
Q
this can be oxidized via a redox reation in which another compound is reduced
A
aldehyde of a reducing sugar
22
Q
only non reducing sugar covered in class
A
sucrose
23
Q
examples of oligo saccharides (3)
A
raffinose
stachyose
verbascose
24
Q
foods containing alot of oligo saccharides
A
beans
peas
bran
whole grains
25
starch is composed of these polys
amylose
| amylopectin
26
glycogen is found here
liver
| skeletal muscle
27
poly which is a dietary fiber and not an energy source
cellulose
28
percent of amylose and amylopectin in startch
15-20
| 80-85
29
glycosidic bonding in amylose
alpha 1-4 (all glucose)
30
this poly is the energy storage in plants
amylopectin
31
consists of glucose moleculeds bonded togther in a highly branched arrangement (plant source)
amylopectin
32
amylopectin has these two types of bonds
alpha 1-4
| alpha 1-6 (branches)
33
energy storage in animals
glycogen
34
this poly has multiple non-reducing ends
glycogen
35
this is the most branched poly
glycogen
36
glycogen has these two types of bonds
alpha 1-4
| alpha 1-6 (branches)
37
why cant cellulose be digested by humans
beta 1-4 bonds
38
what enzyme begins the digestion of amylose and amylopectin
salivary amylase
39
what bond is broken by salivary amylase, and what is formed
a 1-4 bonds
| dextrins
40
t/f: the stomach is the main center of CHO digestion
f
41
the pancreas releases this to continue CHO digestion
pancreatic a-amylase
42
pancreatic a-amylase activity for amylose
breaks a 1-4 bonds
| dextrins are broken down into maltose
43
pancreatic a-amylase activity for amylopectin
breaks a 1-4 bonds
| produces limit dextrins, maltotriose, isomaltose, and maltose
44
pancreatic a-amylase activity stops here on amylopectin
4 residues away from a 1-6 glycosidic bonds
45
maltose is hydrolyzed by this enzyme, a brush border enzyme froming free glucose
maltase
46
maltotriose, isomaltose, and maltose are broken down by these enzymes to glucose
maltase and isomaltase
47
this enzyme is the sole carbohydrase capable of hydrolyzing a 1-6 bonds
a-dextrinase
48
disaccharide digestion occurs here
brush border
49
maltose is digested by
maltase
50
lactose is digested by
lactase
51
sucrose is diegested by
sucrase
52
this enzyme is messing in lactose intolerant people
sucrase
53
type of bond in sucrose
a 1-2
54
this type of starch does not release glucose within the small intestine, but rather reaches the large intesting where it is consumed or fermented by colonic bacteria
resistant starch
55
beano contains this to digest aligosaccharides
a-galactosidase (enzymes)
56
these are poorly absorbed and can cause stomach aches, and diarrhea
sugar alcohols
57
glucose and galactose are absorbed by these two transporders
SGLT1
| Glut2
58
Fructose is absorbed by this transporter
glut5
59
This transporter of glucose and galactose uses sodium and is a form of active transport
SGLT1
60
These two transporters of monos are facilitative transporders
Glut2
| Glut5
61
This mono is more slowly absorbed than glucose
fructose
62
This transporter of monos is the onlyone present on the basal surface of the intestinal cell
Glut2
63
this transporter is transferred to the apical side of the cell when sugar-rih meals are ingested
glut2
64
this hormone causes the translocation of the glut2 transporter from the apical surface of the cell to the inside of the cell
insulin
65
an increase in this substance causes glut2 to join the lumen of the membrane
glucose
66
digestion and absorption of CHO occurs here
brush boarder
67
this transporter is insulin dependent
glut4
68
These are the two transporters with high Km
glut2
| glut4
69
kidney, liver, and brain can work independent of this hormone
insulin
70
storage hormone
insulin
71
how does insulin affect glucose uptake
increases uptake by causing glut4 to bind to apical surface of cell
72
6 steps of translocation of Glut4 to the cell membrane
```
biosynthesis
transported
tethering
docking
fusion
endocytosis
```
73
increase in glood glucose during 2-hour period after consumption of a certain amount of CHO compared with equal CHO from reference food
Glycemic index GI
74
This considers quantity and quality of CHO in a food
glycemic load
75
formula for calculating glycemic load
GI x g of CHO in 1 serving of food
76
examples of things that affect glycemic index
temp
nutrient composition
health of individual
fitness level
77
these monos are used as energy for the liver or made into fatty acids
fructose
| galactose
78
anabolic or catabolic: glycogenesis
anabolic
79
anabolic or catabolic: glycogenolysis
catabolic
80
anabolic or catabolic: glycolysis
catabolic
81
anabolic or catabolic: gluconeogenesis
anabolic
82
anabolic or catabolic: pentose phosphate pathway
anabolic
83
anabolic or catabolic: tricarboxylic acid cycle
catabolic
84
synthesis of glycogen
glycogenesis
85
breakdown of glycogen
glycogenolysis
86
oxidation of glucose
glycolysis
87
synthesis of glucose from non CHO intermediates
gluconeogenesis
88
production of 5-carbon monos and NADPH
pentose phosphate pathway
89
oxidation of acetyl-CoA to CO2 and H2O
TCA cycle
90
what role in CHO metabolism do kinases play
substrate level phosphorylation (ADP to ATP) or phosphorylation of intermediates (hexokinase, pfk))
91
what role in CHO metabolism do dehydrogenases play
Oxidize intermediates utilizing NADH and FADH2
92
number of ATP produced by the breakdown of 1 glucose
32 (max 38 if system is perfect)
93
this is the main source of energy for GI and brain
glycolysis
94
gross atp from glycolysis
2
95
gross nadh from glycolysis
2
96
these enzymes are major regulation sites in glycolysis
PFK (main)
hexokinase
pyruvate kinase
97
galactose enters glycolysis at this step
glucose-6P
98
fructose from adipose tissue enters glycolysis at this step
fructose-6P
99
fructose from the liver (ingested frucose) enters glycolysis at this step
DHAP
| GAP
100
fructose is only metabolized here
liver
101
aerobic fate of pyruvate
TCA cycle
102
anaerobic fate of pyruvate
cori cycle
103
pyruvate can be converted to this AA
alanine
104
the cori cycle happens in these two places
blood cells
| active muscles
105
t/f: more energy is used during gluconeogensis than is gained during glycolysis
t
106
this enzyme converts pyruvate into acetyl CoA while releasing NADH and CO2, and utilizing CoA
pyruvate dehydrogenase
107
TCA cycle accounts for this % of energy production from food
90
108
number of ATP, NADH, and FADH2 produced from one glucose model passing through the TCA cycle
2
6
2
109
this byproduct of CHO metabolism can be used to determine energy production in the body
carbon dioxide
110
two major regulatory enzymes in the TCA cycle
isocitrate dehydrogenase
| a-ketogluterate dehydrogenase
111
t/f: AA can enter the TCA cycle
T
112
T/F: with the utilization of an ATP and CO2 pyruvate can be converted into oxaloacetate
T
113
This much NADH is made during the conversion of pyruvate into acetyl CoA
2
114
What is the purpose of the Cori cycle
turn lactate back into glucose for utilization by skeletal muscle when glucose availability is scarce
115
This system shuttles NADH into the mitochondria from the cytosol by converting NADH to FADH2 through the utilization of G3P and DHAP
G3P shuttle system
116
This system shuttles NADH into the mitochondria from the cytosol by utilizing redox reactions involving malate, and two inner mitochondrial membrane transport proteins
malate-aspartate shuttle system
117
the more efficient method of shuttling NADH into the mitochodria
malate-aspartate shuttle system
118
What is the purpose of the G3P, and malate-aspartate shuttle systems
move energy from NADH from the cytosol into the mitochondria
119
this tissue has disfunctional mitochondria and is found in hibernating animals, infants, and some adults
brown adipose tissue
120
How is energy harvested from NADH and FADH2 in the ETC
NADH gives electrons to complex 1
| FADH2 gives electrons to complex 2
121
oxygen acts as the final electron acceptor of the ETC at this complex
complex 4
122
these are pumped across the inner mitochondrial membrane during the ETC to great an energy gradiant which is used to drive the synthesis of ATP from ADP
H+
123
glycogen makes up this percent of the livers weight
7
124
glycogen makes up this percent of skeletal muscle weight, and this percent of glycogen stores in the body
1%
| 70%
125
T/F: glycogen is formed principally from gluconogenic precursor substances rather than from glucose directly
T
126
glycogen is mostly fromed from this gluconeogenic precursor
lactate produced from red blood cells
127
how does glycogenesis differ in the liver and skeletal muslces
liver uses glucokinase
| muslce uses hexokinase to get glucose into the cell
128
during glycogenesis this reacts with G1P to from an activated compound (UDP-Glucose)
uridine triphosphate
129
T/F: the dephosphorylated form of glycogen synthase is more active than the phosphorylated form
T
130
this hormone facilitates the dephosphorylation of glycogen synthase
insulin
131
this is the primary target of insulins stimulatory effect on glycogenesis
glycogen synthase
132
protein glucose is attached to, to from glycogen
glycogenin (tyrosine residues)
133
Enzyme used form glycogen
Glucosyl transferase (glycogenin)
134
T/F: the less branching on glycogen increases its solubility
F
135
This produces more non-reducing ends on glycogen
branching
136
This occurs during glycogenolysis
non-reducing ends of glycogen are systematically cleaved from the larger molecule to form free glucose
137
what is the significance of branching in glycogen
more free non-reducing ends to allow for quicker release of energy
138
difference in location of hexokinase and glucokinase
hexokinase is only in muscle
| glucokinase is in the liver and pancreas
139
how is the inhibition by G6P different between hexokinase and glucokinase
hexokinase is allosterically inhibited by G6P
| glucokinase is not inhibited by G6P
140
Km differences between hexokinase and glucokinase
hexokinase has a low Km so it functions maximally at fasting blood glucose concentrations
glucokinase has a high Km so it functions maximally when glucose levels are high
141
Induced or not induced by insulin in normal individuals: hexokinase
not
142
Induced or not induced by insulin in normal individuals: glucokinase
induced
143
Induced or not induced by insulin in insulin resistant individuals: hexokinase
not
144
Induced or not induced by insulin in insulin resistant individuals: glucokinase
not
145
Anabolic pathway used to generate NADPH and ribose-5-phosphate to synthesize fatty acid and nucleotide production
hexose monophosphate shunt (HMS)
146
Key enzyme of the hexose monophosphate shunt
G6P dehydrogenase
147
number of NADPH and R5P made during hexose monophosphate shunt
2
| 1
148
NADPH helps to do these things
detoxify
fatty acid synth
reduce oxidative stress
149
the hexose monophosphate shunt is used most in these tissues
mammary glands, adipose, and liver
150
these are a major source of free radicals
mitochondria
151
glucose-6-phosphatase and fructose 1,6 bisphosphatase make it possible to do this
reverse the reactions of glycolysis during gluconeogenesis
152
glucose 6 phosphatase is only found in this organ
liver
153
ATP, NADH, and NADPH are used in this mannor to have a negative or positive modulation of allowsteric enzymes
sense of how much energy is in the body
154
5 substances that are gluconeogenic
```
pyruvate
lactate
glycerol
alanine
glutamine
```
155
this hormone uses covalent modification to regulate the synthesis (decreases) and degredation (increases) of glycogen
glucagon
156
this condition stimulates the release of glucagon
low blood glucose
157
this hormone acts similarly to glucagon in CHO metabolism
epinephrine
158
where does gluconeogenesis occr
liver
159
3 enzymes which act as major regulation factors for glycolysis
hexokinase
PFK
pyruvate kinase
160
4 enzymes which act as a major regulation factors for gluconeogensis
glucose 6 phosphatase
fructose 1,6 bisphosphatase
phosphoenolpyruvate carboxykinase
pyruvate carboxylase
161
nondigestable CHO and lignin that are intact and intrinsic in plants
dietary fiber
162
nondigestable CHO that are isolated, extracted, or manufactured and know to ahve physiological benefits
functional fiber
163
Cellulose is this type of fiber
dietary and functional
164
heterogeneous group of polysaccharide substances, dietary fiber
hemicellulose
165
water-soluble, gel-froming, dietary and functional fiber that is stable at low pH
pectin
166
dietary and functional fiber, insoluble in water, hydrophobic binding capacity, generally poorle fermented by colonic bacteria
structural component of plant
lignin
167
dietary and functional fiber, tree and shrub exudate, composed of sugars and derivatives
gums (hydrocolloids)
168
dietary and functional fiber, water-soluble, inproves glycemic control and lowers cholesterol
B-glucans
169
inulin, oligofructose, fructooligosaccharides
fructans
170
dietary fibers, prebiotics (found in fiber one products)
fructans
171
this fructan can be used to replace fat in recipes
inulin
172
recommended consumption of resistant starch to obtain health benificts
20g/day
173
amylose tightly packed together and cannot be digested or absorbed by humans
resistant starch
174
similar to cellulose in cell walls, found in exoskeletons, and interacts with cholestrol
chitin
| chitosan
175
used as bulking agen or sugar substitue
polydextrose
176
polyglycitol and malitol, found in syrups
polyols
177
functional fiber, mucilage from husk of psyllium seeds, high water binding capacity and provides viscosity
psyllium
178
4 important properties of fiber
solubility in water
water-holding capacity and viscosity
absorption or binding ability
degradability/fermentability
179
this type of fiber dissolves in hot water
soluble
180
this type of fiber doesnt dissolve in hot water
insoluble
181
only three insoluble fibers given in class
lignin
cellulose
hemicellulose
182
soluble fiber can cause gel formation leading two the 4 following
decrease nutrient absorption
increase transit time
decreased digestive function (binding)
decrease in rate of gastric emptying
183
T/F: insoluble fiber can do everything soluble fiber can
F, true in reverse
184
how does fiber aid in disease management
cardiovascular disease
diabetes
obesity and weight control
185
3 characterisitcs of soluble fiber not shared by insoluble fiber
delay gastric emptying
increase transit time
decrease nutrient absorption
186
2 characteristics of insoluble fiber notshared by soluble fiber
decrease transit time
| increase fecal bulk
187
T/F: inadequate intake of fiber is related to diverticular disease, colon cancer, and constibation
T
