Exam 3: GI 4-6 Flashcards
Pathways where energy captured as a result of degradation of energy rich molecules
Catabolic pathways
Pathways that combine small molecules to form more complex energy and often chemical reductions
Anabolic pathways
What are the most abundant organic molecule in nature?
Cabohydrates
What are the functions of Carbohydrates?
- Energy storage
- Storage form of energy
- Cell memb. component
- Structural component
What are carbohydrates made of?
monosaccharides
How many monomers (carbon) make up ribose?
5
How many monomers (carbon) make up glucose?
6
Monosaccharides linked by glycosidic bonds?
disaccharides
3-10 monosaccharides
oligosaccharides
More than 10 monosaccharides
polysaccharides
What are the 4 major dietary carbohydrates
- starch
- glycogen
- saccharose
- lactose
digestion of carbohydrates is achieved by _____ enzymes
pancreatic
Digestion of carbohydrates is finished by enzymes synthesized where?
intestinal mucosa
Where does absorption of carbs take place?
duodenum and upper jejunum
how is absorption of carbs mediated in the SI?
Na dependent transport mech. (SGLT1) apically
Transport of carbs (glucoses) into the blood is passive and facilitated by:
Faciltated transport mech. (GLUT5 and 2) basolaterally
Once in the blood where does glucose travel?
to the liver for energy production
T/F. Glycolysis is a central ATP- producing pathway as it produces energy without O2.
T
What cells take advantave of anaerobic glycolysis
red blood cells and muscle
What do we gain during digestion of carbs.?
2 pyruvate
2 NADH
2 ATP
Once we gain pyruvate from the digestion of carbs, where does it go?
to the mitochondria
Where does the NADH from carb. digestion go?
electron transport chain to become NAD+
During anaerobic glycolysis, how many ATPs are produced from one glucose? and what is it converted into?
2, lactate
During the ETC, how many ATPs are produced for one molecule of NADH?
3
What are other names for TCA?
krebs cycle or citric acid cycle
The final pathway where carbohydrates, AA, and FA converge
TCA
T/F TCA occurs close to the ETC.
T
Is TCA aerobic or anaerobic?
aerobic, b/c oxygen is used as an electron acceptor
What is the function of TCA?
Deliver recuced NADH and FADH2
The production of glucose from non-sugar molecules such as AA, lactate, and glycerol
Gluconeogenesis
T/F Gluconeogenesis is considered reverse glycolysis
F
What are two important tissues for gluconeogenesis?
- kidney
2. liver
Where does glyceral for gluconeogenesis come from?
glycerol phosphate
Where does lactate for gluconeogenesis come from?
pyruvate
Where does AA for gluconeogenesis come from?
TCA cycle, oxaloacetate
A mechanism to store glucose as glycogen in order to mobilize glucose in absence of a dietary source
Glycogenesis
Where are the main stores of glycogen for glycogenesis in the body?
skeletal m. and liver
the process by which glucose is mobilized from glycogen granules in order to be sent into the blood and to other tissues
glycogenolysis
Where does the pentose phosphate cycle occur?
Cytosol
What is produced in the pentose phosphate cycle?
- no atp created or consumed
- produces major portion of NADPH
- ribose 5-phosphate (pentose)
What are the 5 functions of NADPH in physiological processes?
- source of electrons
- carries e- in ETC
- Reduce the enzyme cytochrome P450
- Resp. burst
- synthesis of NO
Where does the breakdown of proteins take place
in the stomach due to pepsin
Where does final absorption of proteins take place?
SI
What are the 5 roles of AA in the body?
- Hydroxylation of Tryptophane to serotonin
2.
