ch18 Flashcards
catabolism
breakdown of large molecules into smaller ones. Energy is generally released
anabolism
synthesis of large molecules from smaller ones. Energy is generally absorbed during anabolism
enzymes in the small intestines that are involved with protein digestion
trypsin and chymotrypsin
Triacyclgercols are hydrolyzed to glycerols and fatty acids by ____ in the _____
lipases in the small intestines
amylase
enzyme involved in the hydrolysis of carbohydrates to monosaccharides
protease pepsin
begins to hydrolyze proteins to amino acids in the stomach
Stage 1 of Catabolism
Digestion
Hydrolysis of large molecules to small molecules.
Molecules then enter its own metabolic pathway to be further broken down.
During catabolism, the amino group (NH2) of a protein is converted into ____
Urea, [NH2)2C=O]
During stage two: monosaccharides, amino acids, and fatty acids are ________
degraded into acetyl groups (CH3CO-), two carbon units bonded to Coenzyme A.
Forms Acetyl CoA
Stage 3 of catabolism
Citric Acid Cycle (mitochondria). The acetyl groups of acetyl CoA are oxides to carbon dioxide. Energy is stored in the bonds of a nucleoside triphosphate and reduced coenzymes.
Stage 4 of catabolism: _______ and _____, produce ____
electron transport chain an oxidative phosphorylation produce ATP.
oxygen combines with ___ and ____ to form water.
hydrogen ions and electrons from reduced coenzymes
ATP is a nucleoside triphosphate formed by….
adding three phosphates to the 5’-OH groups of adenosine, a nucleoside composed of the sugar ribose and base adenine.
Hydrolysis of ATP cleaves….
one phosphate group, forming ADP and hydrogen phosphate (Pi).
Releases 7.4 kcal/mol of energy.
energy change for the phosphorylation of ADP is…
+7.3 Kcal/mol
energy is absorbed
Oxidizing agent
causes an oxidation reaction to occur,
oxidizing agent is reduced
Reducing Agent
causes a reduction reaction to occur,
reducing agent it oxidized.
when a coenzyme gains hydrogen atoms….
the coenzyme is reduced
Oxidizing agent
when a coenzyme loses hydrogen atoms…
the coenzyme is oxidized
Reducing agent
NAD+ reacts with two hydrogen atoms and….
gains one proton and two electrons, with one proton leftover.
NAD+ is reduced or oxidized?
reduced to form a new C-H bod in the product (NADH)
NAD+ serves as a(n) ____
oxidizing agent
NADH serves as a(n)____
reducing agent
FAD is synthesized in cells from___
B2 Riboflavin
FAD -type of agent?
Oxidizing
FADH2- type of agent?
Reducing
Coenzyme A contents a ___ group
sulfhydryl group, making it a thiol (RSH)
formation ot acetyl CoA?
the sulfhydryl group of coenzyme A reacts with acetyl groups to from thioesters. When the acetyl group is bonded to coenzyme A, it produces acetyl CoA.
coenzyme A is synthesized from ____
pantothenic acid (B5)
Net result of glycolysis
2 Molecules of ATP ( 2ATP in step 1 and 3, four ATP in step 7 and 10).
2 Molecules of NADH (step 6)
2 Molecules of Pyruvate
Glycolysis begins with _____ of ATP to form glucose _____, using the enzyme
phosphorylation of ATP to form glucose 6-phosphate, enzyme hexokinase.
[Glycolysis] After the formation of glucose 6-phosphate, ______ occurs, converting it into ____6-phosphate
(enzyme?)
isomerization of glucose 6-phosphate to fructose 6-phosphate
Enzyme: phosphohexose isomerase
[Glycolysis] ____ of fructose 6-phosphate yields fructose ____
Phosphorylation of fructose 6-phosphate yields fructose 1,6-biphosphate.
[Glycolysis] ____of fructose 1,6 phosphate into ____ and ____
Cleavage into dihydroxyacetone phosphate and glyceraldehyde 3-phosphate.
[Glycolysis] Dihydroxyacetone must be….
converted into glyceraldehyde by triose phosphate isomerase
end product of glycolysis
pyruvate
pyruvate is converted to acetyl CoA under…
Aerobic Conditions.
Oxidation of pyruvate by NAD+ w Coenzyme A.
O2 needed to oxidize NADH back to NAD+.
Pyruvate is converted to lactate under…
Anaerobic Conditions.
Not enough O2 to re-oxidize NADH, cells get O2 by conversion to lactate.
Fermentation
glucose to ethanol and CO2
Role of NADH in conversion of pyruvate to lactate?
NADH is the reducing agent
