glycolsis Flashcards
Two types of metabolic pathways
Catabolism
anabolism
Describe catabolic pathways
Breakdown large molecules into smaller ones
release large amounts of energy
oxidative- release H atoms- reducing power
Describe anabolic pathways
Synthesise larger important cellular components from intermediate metabolites
use energy release from catabolism (ATP)
reductive(use hydrogen released in catabolism)
What is the universal product which is the end of many catabolic pathways
Acetyl-CoA
Saliva contains what enzyme
Amylase breaks down starch into disaccharide’s
Pancreas contains what enzymes
amylase breaks down into monosaccharides
Small intestine contains what enzymes and what can epithelial cells have
Disaccharidases attached to simple cuboidal microvilli epithelial cells
Why is there no significant hydrolysis of cellulose in humans
Has beta 1-4 like glycosidic bond humans do not contain enzymes to hydrolyse
In broad terms what kind of bonds are broken in catabolism
Carbon nitrogen
carbon oxygen
No carbon carbon bonds
What coenzyme is reduced during glycolysis
NAD+
What type of phosphorylation to make ATP happens in glycolysis
Substrate level phosphorlytion
All tissues can metabolise glucose but some tissues can only metabolise glucose name some
Red blood cells
neutrophils
innermost cells of kiddie medulla
lens of eye
Central nervous system prefers glucose what can I use as an alternative energy source
Ketone bodies in time starvation but night needs time to adjust
Three ways lactose intolerance occurs
Primary lactase deficiency
secondary lactase deficiency
congenital lactase deficiency
Explain primary lactase deficiency
Absence of lactase persistence allele
highest prevalence in north-west Europe
only occur in adults
Secondary lactase deficiency
Caused by injury to small intestine
e.g. Crohn’s, ulcerative colitis
occurs in both infants and adults
generally reversible
Congenital lactase deficiency
Extremely rare, autosomal recessive defect in lactase gene cannot digest breastmilk
Describe how glucose uptake and from the small intestine through epithelial cells and to capillaries
Active transport intestinal epithelial cells by sodium -dependent glucose transporter one
passive transport via GLUT2 into blood supply
transport by blood supply to target tissues
glucose uptake into target cells via facilitated diffusion using and transport proteins GLUT1-5
GLUT2 found
Kidney
liver
pancreas beta cells
small intestine
GLUT4 found
Adipose tissue, striated muscle
The key regulatory enzyme is
PhosphOfructokinase one
What is a committing step of glycolysis
Glucose becoming glucose-6-phosphate via ATP and hexa kinase
makes glucose negatively charged
prevents back passage across plasma membrane
phosphorylation also increases reactivity
Which step of glycolysis makes NADH
Step five
Where does the energy come to drive the substrate phosphorylation
exogonic reaction release energy
