CHO Flashcards
What are examples of monosaccharides?
Aldoses (Glucose, galactose)
-polyhydroxyl aldehydes
Keotse (Fructose)
-Polyhydroxyl ketone
What are examples of disaccharides?
Sucrose (glucose + fructose)
Lactose (galactose and glucose)
Maltose (glucose and galactose)
What are examples of complex carbs?
Polysaccharides >10 monosacchs
- Starches
- Glycogen
- Fibers
- -Pectin, cellulose, gums
Oligosaccharides 3-10 monosacchs
- Dried beans, peas, lentils
- -rafflinose and stachyose
What are the two forms of Starch?
Amylose and Amylopectin
What is Amylose?
A straight chain form of starch Amylase produces 1-4 linked disacchs (maltose)
What is Amylopectin?
A branched chain form of starch that forms 1-4 and 1-6 linkages (less digectible)
Amylase produces maltose, maltriose, dextrins
What is glycogen?
Storage form of glucose in animals and humans
Highly branched chain
Little to none in diet
(broken down upon slaughter)
Fiber has a nondigestable what?
Linkage between monosaccaharides
What are examples of insoluble fibers and what food sources are they found in?
Cellulose, hemicellulose, lignins
Brown rice, wheat bran, whole grains, fruits, vegetables, legumes, seeds
What is the role of insoluble fibers in cells?
structural fibers in plant cell walls
What are examples of soluble fibers?
Pectins, gums, mucilages, B-glucans, inulin
What is another name for soluble fibers?
Viscous
What is the role of soluble fibers in cells?
cellular fibers
Where do you find soluble fibers?
Whole grains, fruits, vegetables, legumes, seeds and husks
What are the functions of fibers?
Slows stomach emptying "Binding" action (viscous fibers) e.g. cholesterol Exercise for gut muscles Softer stool More rapid waste transit Releases small amount of energy
What is the primary metabolic fuel in humans?
CHO- provide 40-60% of the energy
CHOs are primarily consumed as?
Glucose
-polymers or simple sugars
What enzymes digest starches?
Salivary amylase
Pancreatic amylase
Oligosaccharidases-disaccharidases
What are glycosidases?
Cleave 1 glucose from non-reducing end
-Produce free glucose for transport into Intestinal epithelial cells
What enzymes are found in the mouth and what forms of CHO do they digest?
Salivary amylases
Starch, maltose, sucrose, lactose
What enzymes are found in the stomach and what forms of CHO do they break down?
Amylase form saliva
Dextrin Maltose
What enzymes are found in the small intestine and what forms of CHO do they break down?
Pancreatic Amylase (Maltose) Brush border enzymes (glucose, fructose, galactose)
What enzymes are found in the large intestine and what forms of CHO do they break down?
None
Bacterial microflora ferment cellulose
How does Glucose and galactose get absorbed into the intestine?
Via SLGT1 along with sODIUM
How does Fructose get absorbed into the intestine?
Via facilitate diffussion with the GLUT5 transporter
Do vitamins provide energy?
NO, glucose does
What enzyme is needed in the first step of the break down of glycogen in the krebs cycle and what vitamin is associated with it?
Glycogen phosphorylase; B6
What is PLP?
Active form of B6 Pyridoxal 5’-phosphate
Plamsa PLP is taken up mainly by?
muscle
PLP is mostly bound to what?
glycogen phosphorylase
What is glycolysis?
“Glucose splitting” anaerobic
1 glucose splits into 2 pyruvate molecules
Niacin is important for what enzyme in carbohydrate metabolism (glycolysis)?
Glyceraldehyde Phosphate Dehydrogenase
Thiamin and Niacin are important for what enzyme in carbohydrate metabolism (glycolysis)?
Transketolase ( Foun in pentose phosphate pathway.
Erythrocyte Transketolase activity is used in assessing the status of what vitamin?
Thiamine
Pyruvate dehydrogenase enzyme complex is used in carbohydrate metabolism accompanied by what vitamin?
Thiamine
Pyruvate Carboxylase is dependent upon which enzyme?
Biotin
What is the CHO AMDR and RDA for adults ?
AMDR = 45-65% RDA = 130G/D
What is the Added sugar AMDR and WHO values?
WHO =
What is the AI for Dietary fiber?
Males = 38g/d Females = 25 g/d
What are the different types of substrates that can be used in gluconeogenesis?
Glucogenic amino acids
Glycerol (triglycerides)
Propionate (short chain fatty acids )
What are the primary regulators of blood Glucose?
Insulin
Glucagon
epinephrine (adrenaline)
What is GLUT 4?
a glucose transporter
What stimulates GLUT4 to take up glucose into the adipocytes and myocytes?
Insulin
Sulfonylureas do what?
Inhibit K channels
Induce insulin secretion
What happens in the mechanism of insulin secretion?
K+ channel is inhibitrd -membrane depolarization -stimulatred by glucose Opens voltage-gated calcium channels Calcium induces insulin release via exocytosis
What is TYPE1 DIabetes?
Autoimmune destruction of Beta cells
What is type 2 diabetes?
Peripheral tissue insulin resistance
What is gestational diabetes?
Happens only during pregnancy
what are secondary regulators of blood glucose?
thyroid hormone glucocorticoids growth hormone leptin adiponectin
