Carbohydrate Energy Production 1 Flashcards
What is the most common metabolite?
Acetyl CoA
What are the 4 stages of Catabolism?
- Breakdown of fuel molecules to building block molecules
- Degradation of building blocks to organic precursors
- Kerbs Cycle
- Electron transport and Oxidative phosphorylation
What bonds are broken in the first stage of Catabolism?
C-N
C-O
What bonds are broken in stage 2 of Catabolism and where does it take place?
C-C bonds broken
Intracellular in cytoplasm and mitochondria
What is the general formula of carbohydrates and what groups do they contain?
(CH2O)n
Contain aldose or ketose groups
What are the 3 dietary monosaccharides?
- Glucose
- Fructose
- Galactose
What monosaccharides constitute Lactose?
Galactose and Glucose
Name 3 dietary carbohydrates
- Glucose
- Fructose
- Sucrose
- Lactose
- Maltose
- Starch
- Glycogen
Name 3 bodily components that require Glucose
- Red blood cells
- Neutrophils
- Kidney Medulla
- Lens of the eye
- CNS
What is a normal blood glucose reading?
Around 5mM
How and where are carbohydrates broken down before they reach the small intestine?
Salivary Amylase - Starch/Glycogen broken down to dextrins
Pancreatic Amylase - Dextrins converted to monosaccharides
Name 2 enzymes found in the small intestine and where are they found?
Enzymes are attached to the brush border of Epithelial Cells
- Lactase
- Sucrase
- Pancreatic Amylase
- Isomaltase
Which substance is indigestible, why and what purpose does it serve?
- Cellulose
- No enzyme to break down beta linkages
- Role as dietary fibre to aid movement in GI tract
What are the 3 types of Lactose intolerance and what causes them?
- Primary lactase deficiency - Absence of lactase persistence allele
- Secondary lactase deficiency - Small intestine injury (reversible)
- Congenital lactase deficiency - Autosomal recessive defect in lactase gene
What two ways can sugar be absorbed?
- Active transport using sodium pump glucose transporter (SGLT1)
- Passive transport using glucose transporters from cell to blood
What are Glucose Transporters?
Transport proteins that enable cells to take up glucose from the blood via facilitated diffusion
What are the reactants and products of Glycolysis?
Glucose (6 carbon) forms 2 Pyruvate (3 carbon), 2 ATP and 2 NADH
What are the functions of Glycolysis?
- Oxidation of glucose
- 2 NADH
- 2 ATP from ADP
What are the features of Glycolysis?
- Central pathway of carbohydrate metabolism
- Occurs in ALL tissues (cytosolic)
- Can act anaerobically
Why is Glycolysis reversible?
It uses 3 enzymes
What are the 3 main enzymes in Glycolysis?
- Hexokinase
- Phosphofructokinase-1
- Pyruvate Kinase
Why does Glycolysis have so many steps?
- Easier in small stages
- Efficient energy conservation
- Versatile
- Can be controlled
