Exam 2 Flashcards
In the human diet, the major polysaccharide is….
Starch
In the human diet, the major disaccharides are….
Sucrose (glucose+fructose)
Lactose (glucose+galactose)
In the human diet, the major monosaccharides are….
Glucose, fructose, galactose
What are the primary and secondary causes of lactose intolerance?
Primary: a deficiency of lactase
Secondary: an injury to the mucosa of the intestines
What is the Glycemic Index?
A measure of the effect of dietary carbs on blood glucose levels
What are the types of carbohydrate transporters?
GLUT and SGLT
What molecule carries electrons from catabolism?
NADH
What molecule carries electrons for anabolism?
NADPH
What organ can carry out all major metabolic pathways?
The liver
GLUT4
Stimulated by insulin
assists in glucose uptake into skeletal and cardiac muscle
GLUT2
Found in pancreatic beta cells and the liver
Sodium-Dependent Glucose Transporters
SGLT1 and SGLT2
Active glucose transporters in the gut and in the renal tubules
Where does glycolysis take place?
Cytoplasm
What kind of cells do anaerobic glycolysis?
RBCs
Contracting skeletal muscle
Cancer cells
Hexokinase vs Glucokinase
Hexokinase has a lower Km than glucokinase (hexokinase has higher affinity)
Hexokinase has a lower vmax than glucokinase
PFK-1
Irreversible step
catalyzes the conversion of F-6-P to F 1,6, BP
1 ATP is used
Pyruvate Kinase
Irreversible glycolysis step
Forms ATP
Example of substrate level phosphorylation
What are the 3 fates of pyruvate?
Acetyl-CoA
Lactate
Ethanol (yeast/bacteria)
What are the results of aerobic glycolysis?
2 pyruvate
2 ATP
2 NADH
What are the results of anaerobic glycolysis?
2 Lactate
2 ATP
Glycolysis irreversible steps
Hexokinase/glucokinase
PFK-1
pyruvate kinase
large delta G
glycolysis inhibition
ATP and citrate
Where does the TCA cycle occur
mitochondrial matrix
How does acetyl Coa get made?
pyruvate dehydrogenase complex
Thiamine pyrophosphate
Active form of Thiamine
Without it, causes Beriberi
What are the TCA coenzymes
FAD and NAD
Thiamine pyrophosphate
CoA
What happens with alcohol metabolism in the liver
rapid production
Substrate level phosphorylation
Generation of ATP without oxygen
Glycolysis and TCA
Oxidative phosphorylation
Oxygen is the final electron acceptor
ETC in mitochondria
Chemiosmotic hypothesis
potential energy from ETC is used in oxidative phosphorylation
Reduction Potential
Ability to give up or accept electrons
Midpoint potential
50% oxidized and 50% reduced
Complex I
NADH to CoQ
Complex II
Succinate to CoQ
Cytochome
memebrane bound heme containing proteins
Complex III
CoQH2 to cyt c
Proton pump gradient
Outside more positive and acidic
F0 domain
membrane spanning part of ATP synthase
F1 domain
Matrix of ATP synthase
What do uncouplers do
Increase membrane permeability, heat and stop ATP synthesis
mtDNA
mitochondrial DNA
Pentose Phosphate Pathway products
NADPH, R-5-P, glycolytic intermediates
Oxidative phase of PPP
G-6P to R-5-P and 2 NADPH
Glucose 6- phosphate dehydrogenase
Rate limiting step of PPP
Transketolase and Transaldolase
Enzymes for non oxidative PPP
Where is glycogen stored
Sketetal muscle and live
Glycogen synthesis steps
phosphoglucomutase forming G-1-P
UDP-glucose
Glycogen synthase
How is glycogen synthase attached
alpha 1,4
Branching enzyme
1,6 transferase
Where does gluconeogenesis occur
90% in the liver
10% in the kidneys
mitochondria and cytoplasm
PEPCK
converts oxaloacetate to PEP
What are the 3 major carbon sources for gluconeogenesis
Lactate, amino acids, glycerol
What do double bonds do to the melting point
Lower it
how are lipids broken down in the stomach
gastric lipase
Gluconeogenesis enzymes
Pyruvate carboxylate and F-1,6-BP
What happens when electrons are transferred from NADH to oxaloacetate
Malate
What is formed from Beta-oxidation
fatty acid chain shortened by 2C
FADH2, NADH, acetyl CoA generated
LDL
Bad
HDL
Good lipoprotein
cdk for growth
cdk and cyclin make a complex and phosphorylate Rb to continue cell division
cdk to stop growth
CDK inhibitors stop it from phosphorylating Rb
