Chapter 5 - Cellular Respiration Flashcards
monosaccharide
single carbohydrate molecule (simple sugar)
disaccharide
two monosaccharides bonded together
oligosaccharide
a few monosaccharides bonded together
polysaccharide
many monosaccharides bonded together
glycosidic linkage
- bond between two sugar molecules
- covalent bond formed in a dehydration rxn
glycogen
- energy storage in animals
- made up of many glucose
hydrolysis of polysaccharides into monosaccharides is ____
favored thermodynamically
maltase
catalyzes the hydrolysis of maltose into two glucose
rumen
bacteria required to digest cellulose
lactase
digests lactose
lactose malabsorbers
people who lack lactase
glucose is ____ oxidized to release energy
oxidized
when glucose is oxidized, _____ are ____
high energy electron carriers; reduced
NADH & FADH2
- accept high energy electrons during redox reactions
- oxidized later to deliver electrons in the trnasport chain
- enzymatic cofactors
oxidiation of NADH & FADH2 generates a ____
proton gradient
when glucose is oxidized, it produces ___ & ___
CO2; ATP
glycolysis
- first step in metabolism; occurs in the cytosol
- glucose is oxidized (split in half) to 2 pyruvate molecules by means of phosphorylation
glycolysis requires
2NAD+, 2ATP, enzymes
glycolysis yields a net
2 pyruvate, 2ATP, 2NADH, 2 water, & 2 H+
hexokinase
catalyzes first step in glycolysis
phosphofructokinase (PFK)
- catalyzes thrid step of glycolysis
- transfers a phosphate group from ATP
- irreversible step
- allosterically regulated by ATP
aerobic conditions
- oxygen present
- pyruvate oxidized normally
anaerobic conditions
- no oxygen present
- pyruvate is reduced to lactate to produce NAD+ in order to continue glycolysis
PDC
- pyruvate transported to the mitochondrial matrix to be completely oxidized to CO2
- pyruvate turns into a 2 carbon molecule (activated acetyl unit) to enter the kreb’s cycle
oxidative decarboxylation
molecule is oxidized to release CO2 & produce NADH
coenzyme A
carrier for acetyl unit
high concentration of AMP will ____ PDC
stimulate
prosthetic group
cofactor tightly/covalently bound to an enzyme (ex. vitamins)
krebs cycle
takes the activate acetyl unit to combine it with oxaloacetate and releases 2 carbon dioxide molecules
stage 1 of krebs cycle
acetate fragement is condensed with oxaloacetate to produce citrate
stage 2 of krebs cycle
citrate is oxidized to release carbon dioxideand produce NADH/FADH2
stage 3 of krebs cycle
- oxaloacetate is regenerated to continue the cycle
- GTP is produced (high energy phosphate)
- GTP transfers phosphate group to ADP to create ATP