Biochem- Nutrition I - III Flashcards
List the functions of carboyhdrates.
LEBES
Lipid metabolism
Energy production
Building macromolecules
Energy storage
Sparing Proteins
Define Glycemic index (GI).
The blood glucose after consumption of a test food divided by the iAUC of a reference food containing the same amount of carbohydrate.
GI= 100 x (126/180)
Define Glycemic Load.
The amount of carbohydrates consumed multiply by the rate at which the carbohydrate metabolized and enters the bloodstream.
GL = (GI /100) X g of carbs
State the functions of proteins. Remember at least 4.
Growth and Maintenance
Acts as a messenger
Causes biochemical reactions
Provides structure
Maintains proper pH
Balances fluids
Provides Energy
Transports and stores nutrients.
State the two EER terms and their definitions.
EERM- estimated energy requirement for maintenance — the dietary energy intake that is projected to maintained energy balance in healthy individuals at current levels of body size and physical activity.
DEER- desirable estimated energy requirements- the dietary energy intake that is projected to maintained energy balance in healthy individuals of a defined gender, age, weight, height and level of activity consistent with good health and/or development.
List some characteristics of Macronutrients
- Provide the body with energy and and components needs to maintain its structure and functions
- Carbs, proteins and fats
- Essential nutrients
- Needed in large amounts
List examples of omega-6 and 3 fatty acids.
Omega 6:
Meat
Poultry
Fish
Vegetable oil
Omega 3:
Green leafy vegetables
Canola, walnut or soybean oil
Chia/ flax seeds
List the essential amino acids.
Valine
Leucine
Isoleucine
Phenylalanine
Tryptophan
Lysine
Histidine
Methionine
Threonine
Discuss the role of micronutrients in human and animal nutrition.
Cofactors of metabolism
Coenzymes of metabolism
Genetic control
Antioxidants.
List come characteristics of vitamins.
Complex, essential organic substances
Perform a variety of metabolic functions
Must be derived from the diet
State the Recommended dietary allowance for Thiamine (Vitamin B1) in men and woman.
Men 19yrs & older - 1.2mg
Woman 19yrs & older - 1.1 mg
Pregnant females - 1.4 mg
State the deficiencies for Thiamine (B1).
— Wet beriberi- characterized by edema, heart failure and dyspnea.
— Dry beriberi - plyneuritis and muscle wasting.
Note: deficiency can lead to ATP depletion which affect the brain, nerves and heart first.
Note: Coenzyme for B1 is TPP, thiamine pyrophosphate.
State the RDA for Riboflavin in men and women.
1.3 and 1.1, respectively
Pregnant and lactating females 1.4 — 1.6mg
State the significance of riboflavin (B2).
- Key component of coenzymes needed for energy production, growth of cells and the breakdown of fats, steroids and medication
- Is the cofactor of redox reactions (FMN and FAD)
State the deficiency of Riboflavin.
— Cheilosis, inflammation of lips and fissures of the mouth.
— corneal vascularization
List food highest in Riboflavin (B2)
Beef
Tofu
Salmon
Low fat milk
Mushroom
Almonds
Spinach
State the significance of Niacin (Vitamin B3)
- Utilized in redox reactions ( NAD+ and NADP+)
- Metabolic function is to form the nicotinamide ring of the coenzymes NAD and NADP
—— NAD is a coenzyme for Pyruvate dehydrogenase and a- ketoglutarate dehydrogenase
—— NADP is a important for reactions involving G-6-P and 6-P-D-G dehydrogenase
List foods highest in Niacin (B3)
Tuna
Lean chicken breast
Beef
Lean pork chops
Mushrooms
Brown rice
Green beans
Avocados
Panthothenic acid (Vitamin B5) is a component of what?
State its RDA for males and females.
- Coenzyme A and fatty acid synthase.
- RDA- 5mg and for pregnant and lactating woman 6mg and 7mg respectively.
Pantothenic Acid (B5) deficiency is characterized by?
Dermatitis
Enteritis
Alopecia
Adrenal insufficiency
List the three compounds of pyridoxine (B6).
State the significance of B6.
Pyridoxine
Pyridoxal
Pyridoxamine
Significance: critical for formation of red blood cells.
What is the RDA for pyridoxine (B6) for both men and females.
Men ages:
14-50 — 1.3mg
51+ — 1.7mg
Women ages:
14-18 — 1.2mg
19-50 — 1.3mg
51+ — 1.5mg
Pregnant and lactation - 1.9-2.0mg
State the deficiency of Pyridoxine. (Vitamin B6)
Sideroblastic anemia
Hyperirritability
Convulsions
Peripheral neuropathy
Mental confusion
State the coenzyme for folic acid (B9) and list its RDA for males and females.
- Tetrahydrofolate
- RDA -
Males and females 19yrs & older — 400 mcg DFE
Pregnant and lactation — 600 and 500 mcg DFE respectively.
State the significance of Colbamin (Vitamin B12)
— Essential for erythropoiesis
— development and functions of nervous system
— Binds to food. (In the stomach, it is unbind by HCL and digestive enzymes and release in it free from)
— binds to an intrinsic factor to be further digested in the small intestine.
What is the deficiency for Vitamin B12 (Cobalamin)
— Pernicious anemia
— Degeneration of the spinal cord
— Nerve damage:
A) methocobalamin required for the conversion of homocysteine into methionine.
B) cause lack of methionine for myelin production.
What are the enzymes dependent on Cobalamin?
Methylmalonyl CoA mutase (excreted in urine)
Leucine aminomutase
Methionine synthase - needed for myelin production.
What are functions of vitamin A?
- Plays an integral role in differentiation and proliferation of epithelial cells in the eyes, salivary glands and genitourinary tract.
- A precursor to all- trans retinoic acid
- Stimulates T- lymphocyte differentiation and B- lymphocyte activation in response to immune stimuli.
State the deficiencies of Thiamin (vitamin A)
Xerophthalmia
Keratomalacia
Follicular hyperkeratosis (flaky skin)
What are some food rich in Vitamin A?
Carrots
Tuna
Butternut squash
Spinach
Sweet potato
Lettuce
State the RDA and deficiencies of Vitamin D.
RDA-
Children- 10 mcg
Adults- 20 mcg
Pregnant females - 25 mcg
Deficiencies-
Rickets and osteomalacia
Which vitamin is combines with an intrinsic factor protein?
B12
Describe how Vitamin B12 is absorbed in the digestive system?
— B12 binds to the proteins.
— In the stomach, HCL acid and enzymes unbind the B12 from the food.
— B12 is then bind to an intrinsic protein and further absorbed into the small intestine.
What is the recommended intake for a healthy diet?
Total fats- not exceed 30%
Saturated fats - no less than 10%
Trans fats - less than 1%
Sugars - less than 10%
Salt - less than 5g
Describe the absorption of fat soluble vitamins.
- Fat soluble vitamins are absorbed as micelles.
- After absorption, they are packages into the chylomicrons and secreted into the lymph vessels and then the blood.
- The chlylomicrons and broken down by lipoprotein lipase and release them into the tissue for storage and use.
Which of the following are is the circulating form and active form of vitamin D?
A) ergocalciferal
B) cholecalciferal
C) 25- hydroxyvitamin D
D) 1,25- dihydroxyvitamin D
Circulating form- C
Active form - D
List the functions of Vitamin E.
Antioxidant that prevents oxidation of fatty acids
Protects lipids in membranes from oxidative agents
Protects erythrocytes from hemolysis
State the significance of Vitamin C.
- Facilities the conversions of bile salts and lower cholesterol levels.
- Increases the absorption of iron in the gut
- Cofactor for dopamine beta hydroxlase
State the deficiency of Vitamin C and its RDA requirements.
A) scurvy
B) 60 mg/day - adults
40 mg/day - child
State the signifance of folic acid (Vitamin B9)
— Formation of RNA and DNA and protein metabolism
— involved in the break downs of homecysteine
— needed to produce red blood cells and important in pregnancy
What is the significance for Thiamine (Vitamin B1)
It is cofactor for:
A- ketoglutarate
Pyruvate dehydrogenase
Transketolase
Branch of ketoacid dehydrogenase
State the significance of Biotin (Vitamin B7)
— metabolism of fats, proteins, carbohydrates
— functions as a coenzyme in reactions involving CO2
Eg. pyruvate carboxylase, propionyl CoA carboxylase, Acetyl CoA carboxylase.
