test 2 Ch 13 Flashcards
Pyruvate Dehydrogenase complex
enzyme complex in mitochondrial matrix that converts pyruvate to acetyl coA and CO2 and also reducing NAD+ to NADH
Glycogen
polysaccharide of glucose storage in animals
Phophofructokinase
regulatory enzyme in glycolysis, catalyzed phosphorylation of fructose-6-phosphate to fructose-6-biphosphate
fructose-1,6-biphosphatase
enzyme in gluconeogenesis that catalyzes the conversion of fructose-1,6-biphosphate to fructose-6-phosphate
active when phosphofructokinase is inhibited, allowing gluconeogenesis
3 stages of food breakdown
digestion -> conversion to acetyl CoA -> complete oxidation
steps of cellular respiration
complete oxidation of glucose to CO2 and H2O from
1) glycolysis
2) pyruvate dehydrogenase complex
3) citric acid cycle
4) oxidative phosphorylation
Fermentation
Pyruvate or another organic molecule is reduced by NADH to recyle NAD+ for glycolysis, happens in anaerobic environments.
Metabolic regulation
allows cells to switch between catabolic and anabolic reactions based on cellular needs
Gluconeogenesis
Generates glucose from non-carbohydrate sources like amino acids
Relevant during fasting/exercise
what breaks down glycogen for energy usage?
glycogen phosphorylase
Metabolic network
interconnected system of biochemical reactions, metabolites serve as nodes and reactions as connections
Fatty acid oxidation
fatty acids broke down in mitochondria to generate acetyl CoA
Substrate level phosphorylation
direct transfer of a phosphate group from substrate to ADP to form ATP
occurs in Citric acid cycle and glycolysis
Citric acid cycle products per cycle
CO2
GTP
3 NADH
FADH2
Oxaloacetate
four C molecules that combines with acetyl CoA to from citrate at beginning of Citric acid cycle
dehydrogenase
enzyme that catalyzes oxidation of a molecule by removing Hydrogens and electrons
Kinase
enzyme that transfers phosphate to a molecule from ATP
glycolytic enzymes
10 enzymes in glycolysis that couple oxidation to energy storage
Mutase
catalyzes the shifting of a chemical group from one position to another within the same molecule
Isomerase
catalyzes rearrangement of bonds to make isomer of a molecules
steps 2 and 5
Cleavage phase
splitting of a 6C molecule to 2 3C molecules
NAD+
must be in high conc for reactions to occur
accepts electrons for oxidation
Proton motive force
electrochemical gradient created by pumping of electrons across inner membrane during ETC
Investment phase of glycolysis
2 ATP consumed to phosphorylate glucose to fructose-1,6-biphosphate
GDP
Put into citric acid cycle, can transfer the phosphate to ADP to form ATP
Citrate
six C molecules formed from acetyl CoA and Oxaloacetate in first step of CAC
FADH2
reduced electron carrier that donates electrons to ETC, less ATP than NADH
Glucose 6 Phosphate
first intermediate in glycolysis
Glucose 1 Phosphate
intermediate formed during glycogen breakdown before converted to G6P
Metabolic adaptation during fasting
Acetyl CoA derived from fatty acids rather than glucose
1,3-Biphosphoglycerate
high energy intermediate in glycolysis, donates P to ADP to form ATP in substrate level phosphorylation
reversible step 3
Adipocytes
Specialized cells that store energy in the form of fat droplets
Glycogen Phosphorylase
enzyme that breaks down glycogen by removing units as glucose-1-phosphate which then turns into glucose-6-phosphate
Positive feedback
ADP AMP active enzymes like phosphofructokinase activation
fat droplets
triglyceride energy storage for fasting/exercise
Intermembrane space
region where protons accumulate creating a gradient
inner mitochondrial membrane
houses ETC and ATP synthase
Energy investment in Gluconeogenesis
4 ATP and 2 GTP, very energetically unfavorable
Feedback inhibition
ATP inhibits phosphofructokinase
3 phases of glycolysis
1) investment phase
2) cleavage phase
3) energy generation phase
what keeps glucose in a cell
phosphorylation gives a negative charge which makes it unable to travel through the membrane
