Introduction to Metabolism and Nutrition Flashcards
Functions of vitamins
Enzyme cofactors
Antioxidants
Ligands for hormone receptors
Functions of minerals and trace elements
Bone mineralization
Muscle contraction
Production of ATP, enzyme, and protein cofactors
Cellular transport
Components of carbohydrates
Mono, di, and poly saccharides
Fiber
Function of carbohydrates
Energy production
Function of amino acids
Protein synthesis
Carbons for glucose
Function of fats
Energy production
Absorption of fat soluble vitamins
Prostaglandin synthesis
Components of cell membrane
What is the effect of consumption of trans fatty acids
High LDL
Low HDL
What is the effect of saturated fatty acids?
High LDL
Little effect on HDL
What is the effect of monosaturated fatty acid?
Low LDL
Maintain or increase HDL
What is the effect of omgea-6 fatty acids
Low LDL
High HDL
Provide arachidonic acid = precursor of leukotrienes and prostaglandins
What is the effect of omega 3 fatty acids
Little effect on LDL and HDL
Supress cardiac arrhythmia
Reduce serum triglycerides
Decrease tendency of thrombosis
Lower blood pressure
What fatty acids lead to a decrease in incidence of coronary artery disease
monosaturated fatty acid
Polysaturated omga-3
Polysaturated omega-6
What are AMDRs
Acceptable Macronutrient Distribution Range
What are the beneficial effects of fiber
Reduces consipation –> reduces risk for diverticulitis
Increases bowel motility –> reduces risk for colon cancer
Decreases absorption of dietary fat and cholesterol –> reduces risk for cardiovascular disease
Delays gastric emptying
What are DRIs?
Dietary reference intake
Set of dietary reference values designed to prevent deficiencies and maintain health
Refer to long-term average daily nutrient intakes
Designated for specific age group, physiologic states, and gender
What are the dietary reference intake (DRI) standards?
Estimated average requirement
Recommended dietary allowance
Adequate intake
Tolerable upper level intake
What is EAR?
Estimated average requirement
Average daily intake level adequate for 50% of the healthy individuals in a specific life stage and gender group
What is RDA?
Recommended Dietary Allowance
Average daily intake level adequate for almost all healthy individuals in specific life stage and gender group
What is AI?
Adequate intake
Estimated range of intake when RDA or EAR cannot be established due to insufficient scientific evidence
What is the only DRI value that is a range?
AI- Adequate intake
What is UL?
Tolerable upper level intake
Highest average daily intake level with no adverse effects to almost all individuals (useful supplements and fortified foods)
kcal/g of carbs, fats, and proteins
Carbohydrates: 4 kcal/g
Fats: 9 kcal/g
Proteins: 4 kcal/g
What is DIT?
Diet induced thermogenesis
Energy expenditure process of food
What are the 3 main uses of energy in the human body?
Resting metabolic rate (RMR)
Thermic effect of food
Physical activity
What is RMR?
Resting metabolic rate
Energy expenditure of a resting, post-absorptive individual
What is the thermic effect of food?
Energy expenditure to process food
What is included in physical activity?
Energy expenditure during exercise
Amount of expenditure depends on duration and intensity
What is TEE?
Total energy expenditure over a 24 hour period
Is equal to RMR + TEF + Physical activity
If TEE is = intake
You have energy balance
If TEE is greater than intake?
Use use stores of energy –> weight loss
If TEE is less than intake
Store excess –> weight gain
TEE is equal or greater than intake
By increasing physical activity and/or decreasing energy intake
Fatty acids and carbs are stored in the body as
Triacylglycerols (TAGs) in adipose tissue
Carbohydrates are stored in the body as
Glycogen
Glycogen vs Triacylglycerols
Glycogen is stored in muscle and liver and are more hydrated
Triacylglycerols are stored in adipose tissue
BMI is calculated as
Weight (kg)/ [height (m)]^2
Weight (lb)/ [height (in)]^2 x 703
What is BMI values are considered overweight and obese
Overweight: 25-29.9
Obese: 30+
What is metabolism?
Sum total of chemical and physical changes
What are the goals of metabolism?
Energy generation and synthesis of macromolecules
Catabolic pathways require ATP ___
Anabolic pathways require ATP ___
Catabolic: ATP synthesis (ADP + Pi –> ATP)
Anabolic: ATP hydrolysis (ATP + H2O –> ADP + Pi or AMP + PPi)
If the energy change of a cell is close to 1
The cell is energy efficient
If the energy of a cell is close to 0
The cell is energy depleted
If ATP levels are low, __ pathways are on
Catabolic
If ATP levels are high, __ pathways are on
Anabolic
How is metabolism regulated?
Substrate availability and accessibility
Enzyme activity
How can enzyme activity be regulated?
Allosteric regulation
Covalent modification
Induction and repression by hormones
Allosteric bonds are ___ and have a __ effect
Non-covalent bonds
Transient effect
The effector in allosteric regulation can be
Substrate or product in the same pathway
What are types of allosteric regulation
Feed-forward stimulation
Feed-back inhibition
Allosteric regualtion is __ and __ communication
fast acting and short-range
Allosteric regulation allows enzymes and pathways to respond to __ signals
Intraceullar signals
Covalent modification has a __ and __ effect
Reversible and transient effect
Covalent modificaiton includes
Phosphorylation/dephosphorylation by kinases and phosphatases
Kinases and phosphatases are regulaed by
Extracellular signals (hormones)
Covalent modification is __ and __ communication
Fast-acting and long-range communication
Covalent modification allows cell to respond to ___ signals
Extracellular signals
Induction and repression leads to
Increase or decrease in intracellular enzyme levels (via mRNA and protein synthesis)
How does induction and repression work?
Alters number of active sites in cell
Reduction and repression has a __ effect
Permanent
Induction and repression is mediated by
Hormones
Induction and repression are ___ and ___ communication
Slow acting and long range
Induction and repression allow cells to respond to ___ signals
Extracellular
What is the committed step of a reaction?
First irreversible reaction unique to the pathway
What is the most highly regulated enzyme in a pathway?
The enzyme catalyzing the committed step
