carbo Flashcards
1
Q
The word carbohydrate is derived from the French word
A
hydrate de carbone.
2
Q
are more appropriately defined as polyhydroxy aldehydes, ketones, alcohols or acids,
A
carbohydrates
3
Q
Carbohydrates represent 75% of plants’ dry weight indicating that _______ are characteristically carbohydrates.
A
plant tissues
4
Q
photosynthesis
A
CO2 + 6H20 + 673 kcal <—-> C6H12O6 + 6H20
5
Q
Only ________ carbohydrates are present in particular tissues (blood,
liver and muscle).
A
1-1.50%
6
Q
monosaccharides with aldehyde group
A
- glucose
- galactose
- mannose
7
Q
monosaccharides with ketone group
A
- fructose
8
Q
hexoses:
A
- glucose
- fructose
- galactose
9
Q
most important sugar in nutrition; major end product of
carbohydrate digestion in non-ruminants
A
glucose
10
Q
only important ketose in nature; the sweetest of the carbohydrates; 75% of sugar in honey is _______
A
fructose
11
Q
component of milk sugar
A
galactose
12
Q
pentose:
A
- D-ribose
- D-xylose, D-arabinose
13
Q
disacchardies:
A
- maltose
- cellobiose
- sucrose
- lactose
14
Q
two α-D-glucose units joined by α-1,4- glycosidic bond
A
maltose
15
Q
two β-D-glucose units joined by β-1,4- glycosidic bond
A
cellobiose
16
Q
glucose + fructose
A
sucrose
17
Q
glucose + galactose
A
lactose
18
Q
trisaccharides:
A
raffinose
19
Q
tetrasaccharides:
A
stachyose
20
Q
pentasaccharide:
A
verbascose
21
Q
galactose + glucose + fructose
A
raffinose
22
Q
raffinose + glucose
A
stachyose
23
Q
raffinose + two glucose
A
verbascose
24
Q
repeating units of maltose or glucose
A
starch
25
-with straight chain joined by α-1,4 linkage;
-reserve carbohydrate in plants;
-abundant in cereal grains/seeds;
-livestock primary energy source
starch
26
2 forms of starch
amylose, amylopectin
27
-Animal starch
-α-D-glucose units;
-structure similar to amylopectin of starch but highly branched
glycogen
28
-most abundant polymer in the plant kingdom
cellulose
29
-basic structure of plant cell walls
-β-D-glucose units joined by β-1,4 linkage
-resistant to animal digestive enzyme
-but susceptible to microbial enzyme cellulase.
cellulose
30
group of complex carbohydrates that are closely associated with cellulose;
- also in plant cell wall
hemicellulose
31
- not a true carbohydrate;
- encases the cellulose and
hemicellulose providing structural support and mechanical strength
to plants;
- resistant to both animal digestive and microbial enzymes.
lignin
32
glucose + glucose, by a-1,4- glycosidic linkage
maltose
33
The dietary carbohydrates of particular importance in non-ruminants are
___________________ since these are digestible.
amylose, amylopectin, lactose and sucrose
34
The dietary carbohydrates have to be hydrolyzed into ____________ for absorption
glucose, galactose
and fructose
35
_____________lack the necessary enzymes for digestion of non-
starch polysaccharides (NSP).
Non-ruminant animals
36
- Some enzymatic digestion
of starch occurs in the
mouth, due to the action of
the enzyme salivary ____
- ________ starts to break the
long glucose chains of starch
into shorter chains, some as
small as maltose.
amylase
37
Most carbohydrate digestion occurs in the ___________
small intestine
38
is secreted from the pancreas into the small intestine, and
like salivary amylase, it breaks starch down to small oligosaccharides and maltose
pancreatic amylase
39
The rest of the work of carbohydrate digestion is done by enzymes produced by the _______, the cells lining the small intestine.
enterocytes
40
Maltose is digested by __________,
forming 2 glucose molecules
maltase
41
Lactose is digested by _____, forming glucose and galactose
lactase
42
Sucrose is digested by ______,
forming glucose and fructose
sucrase
43
____________ are converted to glucose in the liver.
Fructose and galactose
44
Once absorbed carbohydrates pass through the liver, ______ is the main form of carbohydrate circulating in the bloodstream.
glucose
45
Undigested carbohydrates in the small intestine, mainly fiber, pass into the _________
large intestine
46
No enzymatic digestion of carbohydrates
large intestine
47
__________ living in the large intestine ferment carbohydrates
Bacteria
48
The diet of _______ is
composed of large amounts of
carbohydrates in the form of
cellulose and hemicellulose
(largely from roughage) and
some amounts of starch and
mono and disaccharides.
ruminants
49
The ___________ play a
major role in the degradation of
carbohydrates and its eventual
absorption.
rumen microflora
50
in cellulose digestion of microbial fermentation, it produces
acetate, proprionate, butyrate
51
The _______________ are absorbed directly across the rumen wall and eventually metabolized as source of energy.
volatile fatty acids (VFA)
52
The production of high amounts of _________ is a concern not only from the standpoint of efficiency of carbohydrate digestion but also with respect to
its effect to the environment, particularly the destruction of the ozone
layer.
methane CH4
53
For animals producing milk to be processed into butter, it is important that
they be fed diet that effect reasonably high production of
acetic acid
(feeding hay).
54
On the contrary, fattening animals should be fed diet that favor production
of
propionic acid (feeding grains).
55
Basic processes through which energy rich compounds pass
1. glycolysis
2. tricarboxylic acid (krebs/citric)
3. oxidative phosphorylation
56
* The energy currency in the animal’s body
* The energy source for myriad of reactions
* Gives and receives energy during the process of energy metabolism
* Carrier of phosphoryl group from high to low energy compound
* Compounds analogous to ATP: guanine triphosphate (GTP), uridine
triphosphate (UTP), and cytidine triphosphate (CTP)
ATP
57
Electron carriers in the biological oxidation-reduction process
NAD, NADH2, FAD, NADP
58
Compounds formed in the different pathways of energy
metabolism
1. Adenosine triphosphate
2. carbon dioxide
3. water
59
anerobic process which
means that it proceeds
without the need for oxygen
glycolysis
60
Sequence of chemical
reactions in which the
acetyl portion of Acetyl
CoA is degraded into CO2
and H2
tricarboxylic acid cycle
61
- The reactions occur in
the matrix of
mitochondria
* Reactions are aerobic
(oxygen is involved)
tricarboxylic acid
62
is the only VFA found in appreciable quantities in the
peripheral circulation; complete metabolism of acetate yields 12 moles
ATP
acetic acid
63
- is removed from the portal circulation by the
liver and then is converted to glucose;
- it serves as the primary source of
glucose for the ruminants;
- the ATP yield in the complete metabolism of
__________ is 17 moles per mole pyruvate or 34 moles glucose
equivalent
propionic acid
64
- is absorbed as ketone body and metabolized as Acetyl CoA;
- the net ATP yield upon its complete oxidation is 25 mole.
butyric acid
65
metabolism of volatile fatty acids
1. acetic acid
2. propionic acid
3. butyric acid
66
* formation of glycogen from glucose
* prevents marked elevation of blood sugar
* Facilitated by insulin
glycogenesis
67
* reconversion of glycogen into glucose
* prevents a condition of low blood sugar
* ____________ in the muscle is facilitated by the hormone
epinephrine and glucagon
glycogenolysis
68
* The synthesis of glucose from non-carbohydrate sources
(e.g. amino acids and glycerol)
* is stimulated by the hormones glucagon, growth hormone,
epinephrine, and cortisol
Gluconeogenesis
69
* The amount of carbohydrate that is formed as glycogen is
limited.
* When glycogen stored has reached the maximum (1.5%),
carbohydrates are then stored as fat.
* Stimulated by insulin
conversion of glucose to fat
70
metabolic conversions of carbohydrates
glycogenesis, glycogenolysis, gluconeogenesis, conversion of glucose to fat
