Term
| What classifies as a simple carb? |
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Definition
| Monosaccharides and disaccharides |
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Term
| What classifies as a complex carb? |
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Definition
| oligosaccharides and polysaccharides |
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Term
| In what direction does the OH group on the chiral carbon of a D-sugar point? |
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Definition
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Term
| In what direction does the OH group on the chiral carbon of an L-sugar point? |
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Definition
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Term
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Definition
| monosaccharide containing an aldehyde |
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Term
|
Definition
| monosaccharide containing a ketone |
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Term
| What is the anomeric carbon? |
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Definition
| the carbon with the carbonyl group attached |
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Term
| What is the chiral carbon? |
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Definition
| a carbon with 4 different atoms/groups attached |
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Term
| What are polysaccharides? |
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Definition
| long strings or branches of monosaccharides attached by glycosidic bonds |
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Term
| Why is branching useful in polysaccharides? |
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Definition
| it provides a larger number of ends from which to cleave |
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Term
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Definition
| non-digestible complex CHO |
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Term
| What are the characteristics of insoluble fibre? |
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Definition
- remains intact though intestinal tract
- does not dissolve in water
- decrease transit time
- increase fecal bulk |
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Term
| What are the characteristics of soluble fibre? |
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Definition
- forms gel
- dissolves in water
- delays gastric emptying
- decrease nutrient absorption |
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Term
| What is water-holding ability? |
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Definition
| Ability to hold water and become a viscous solution |
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Term
| What is adsorptive ability? |
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Definition
| ability to bind enzymes and nutrients |
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Term
| What is the overall health benefit of fibre? |
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Definition
| Maintains function and health of the gut |
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Term
| What are the health benefits of insoluble fibre? |
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Definition
- lowers constipation
- stimulates muscle contraction to break down waste
- decreases risk of bacterial infections
- more efficient bowel movements |
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Term
| What are the health benefits of insoluble fibre? |
|
Definition
- lowers constipation
- stimulates muscle contraction to break down waste
- decreases risk of bacterial infections
- more efficient bowel movements |
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Term
| What are the health benefits of soluble fibre? |
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Definition
- increases satiety
- delays gastric emptying
- has possible benefits for long term weight control |
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Term
| What is the function of a-amylase? |
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Definition
| breaks down a-1,4-glycosidic bonds |
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Term
| What is the function of alpha-dextrinase? |
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Definition
| breaks a-1,6-glycosidic bonds to produce 2 glucose |
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Term
| What is the function of maltase? |
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Definition
| breaks down maltose into 2 glucose |
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Term
| What is the function of invertase? |
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Definition
| breaks down sucrose into fructose and glucose |
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Term
| What is the function of lactase? |
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Definition
| breaks down lactose into galactose and glucose |
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Term
| What are the fates for glucose after monosaccharide absorption? |
|
Definition
- 15% leaks back into lumen
- 25% diffuses into circulation via basolateral membrane
- 60% transported into circulation by GLUT2 |
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Term
| What are the main functions of monosaccharide absorption? |
|
Definition
- carbohydrates spare protein
- prevents breakdown of proteins for energy
- prevents ketosis
- breakdown of fat for energy, makes body acidic
- only source of energy for the brain
- ensures growth of healthy bacteria in the gut |
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Term
| What are the three specific fates of glucose in a cell? |
|
Definition
1. enters glycogenesis for energy storage
2. enters glycolysis for energy production
3. enters hexose monophosphate shunt to generate precursors for biogenesis |
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Term
| What enzyme is used in glycogenesis and what does it do? |
|
Definition
glycogenin
- serves as a scaffold on which to build glycogen stores
- attaches glucose molecules to itself |
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Term
| When does the Cori Cycle occur? |
|
Definition
- when lactate is produced
- transported back to liver for gluconeogenesis
- allows pyruvate to be converted back into glucose |
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Term
| Describe the anaerobic pathways of pyruvate. |
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Definition
1. pyruvate is converted into lactic acid - regenerates NAD+ which allows first part of glycolysis occur
2. yeast can break down pyruvate into CO2 and ethanol which regenerates NAD+ |
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Term
| Why is the hexose monophosphate shunt important? |
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Definition
| important for NADPH production and ribose synthesis |
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Term
| Which phase of the shunt is irreversible? |
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Definition
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Term
| What phase of the shunt is highly reversible? |
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Definition
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Term
| What happens to the shunt when there are high levels of cellular NADPH? |
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Definition
| NADPH inhibits the enzyme and shuts down the shunt |
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Term
| What is the function of glucose-6-phosphate dehydrogenase in the shunt? |
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Definition
| needed in oxidative phase to shuttle the molecule to non-oxidative state |
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Term
| What are the two general steps of the Kreb's cycle? |
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Definition
1. decarboxylation
2. dehydrogenation |
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Term
| What is the energy yield of the Kreb's cycle from ONE acetyl CoA? |
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Definition
- 3 NADH = 9 ATP
- 1 FADH2 = 2 ATP
- 1 ATP
to equal: 12 ATP |
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|
Term
| What is the net total yield of energy from one molecule of glucose? |
|
Definition
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Term
| Where does gluconeogenesis occur? |
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Definition
| Primarily the liver, can also occur in the kidney |
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Term
| What do the main enzymes do in gluconeogenesis? |
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Definition
| bypass the irreversible steps of glycolysis |
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|
Term
| Where does the first step of gluconeogenesis occur? |
|
Definition
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|
Term
| What is the first step of gluconeogenesis? |
|
Definition
- moving oxaloacetate out of the mitochondria into cytoplasm
- must be converted to malate then back to oxaloacetate |
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