Chapter Questions - Nutrition, Metabolism, and Body Temperature Regulation
What are the six major nutrients
Carbohydrates, proteins, fats, water, minerals and vitamins
Why is it important to include cellulose in a healthy diet even though we cannot digest it?
It provides fiber, which is important for moving feces along the colon and defecation.
How does the body use triglycerides? Cholesterol?
Triglycerides are used for ATP synthesis, body insulation and protective padding and to help the body absorb fat soluable vitamins.
Cholesterol is the basis of our steroid hormones and bile salts, it also stabilizes cellular membranes
John eats nothing but baked bean sandwiches. Is he getting all the essential amino acids he needs in this restricted diet?
Beans and grains are good sources of protein but neither is a complete one. However together they provide all the essential amino acids
Vitamins are not used for energy fuels. What are they used for?
Vitamins serve as the basis of coenzymes, which work with enzymes to complete metabolic reactions
Which B vitamin requires the help of a product made in the stomach to be absorbed? What is that gastric product?
Vitamin B12 intrinsic factor to be absorbed by the intestines
Which mineral is essential for thyroxine synthesis? For making bones hard? For hemoglobin synthesis?
Iodine is essential for thyroxine synthesis. Calcium in the form of bone salts is needed for making bones hard. Iron is needed for hemoglobin synthesis
What is redox reaction?
A redox reaction is a combination of an oxidation and reduction reactions, as one substance is oxidized, another is reduced.
How are anabolism and catabolism linked by ATP?
Some of the energy released during catabolism is captured in the bonds of ATP, which provides the energy needed for the constructive activities of anabolism.
What is the energy source for the proton pumps of oxidative phosphorylation?
The energy released during the oxidation of food fuels is used for the proton pumps of oxidative phosphorylation
Briefly, how do substrate-level and oxidative phosphorylation differ?
In substrate-level phosphorylation high energy phosphate groups are transferred directly from phosphorylated intermediates to ADP to form ATP.
In oxidative phosphorylation electron transfer proteins forming part of the mitochondrial cristae use energy released during oxidation of glucose to create a steep gradient for protons across cristae membrane, gradient energy is captured to attach phosphate to ADP
What happens in the glycolytic pathway if oxygen and pyruvic acid are absent and NADH + H+ cannot transfer it’s “pick-up” hydrogen to pyruvic acid?
If oxygen is not available the glycolysis will stop because the supply of NAD+ is limited and glycolysis can continue only if the reduced coenzyme (NADH + H+) formed during glycolysis are relieved of their extra hydrogen
What two major kinds of chemical reactions occur in the krebs cycle, and how are these reaction indicated symbolically?
Oxidation and decarboxylations are common in the Krebs cycle.
Oxidation is indicated by the reduction of the coenzyme NAD or FAD. Decarboxylations is indicated by the removal of CO2 from the cycle.
What name is given to the chemical reaction in which glycogen is broken down to its glucose subunits?
Glycogenolysis is the chemical reaction in which glycogen is broken down to its glucose subunits
What does carbo loading accomplish?
Carbo loading forces the skeletal muscles to store glycogen than normal
Which part of triglyceride molecules enters the glycolytic pathway?
Glycerol, a breakdown molecule of fat metabolism, enters the glycolytic pathway
What is the central molecule in fat metabolism?
Acetyl CoA is the central molecule in fat metabolism
What are the products of beta oxidation
The products of beta oxidation are Acetyl CoA, NADH+ + H+ and FADH2
What does the liver use as its substrates when it synthesizes nonessential amino acids?
The liver uses keto acids drained off the krebs cycle and amino groups as substrates when it synthesizes nonessential amino acids
What happens to the ammonia removed from amino acids when they are used for energy fuel?
Ammonia removed from amino acids when they are used for energy fuel are combined with carbon dioxide to form urea, which is then eliminated by the kidneys
Which three organs or tissues are the primary effector organs determining the amounts and directions of interconversions in the nutrients pools?
The liver, skeletal muscles and adipose tissue are the primary effector organs determining the amounts and directions of interconversions in the nutrients pools
Generally speaking, what kinds of reactions and events characterize the absorptive state? The postabsorptive state?
Anabolic reactions and energy storage characterize the absorptive state. Catacolic reactions such as lipolysis and gylcogenolysis and glucose sparing characterize the postabsoptive state
Which hormone is glucagon’s main antagonist?
glucagon’s main antagonist is insulin
Which event increases both glucagon and insulin released?
A rise in amino acid levels in the blood increases both glucagon and insulin release
If you had your choice, would you prefer to have high blood levels of HDLs or LDLs? Explain your answer.
High HDL's would be preferable because the cholesterol these particles transport are destined for the liver and elimination from the body
What is the maximum recommended cholesterol level for adults?
The maximum recommended cholesterol level for adults 200 mg/dl of blood or lower
What are trans fats and how do they affect LDL and HDL levels?
Trans fats are oils that have been hardened by hydrogenation to make them more solid. They are unhealthy because they cause LDLs to increase and HDLs to decrease. This is the opposite of what is wanted.
What three groups of stimuli influence short-term regulation of feeding behavior?
The three groups of stimuli influence short-term regulation of feeding behavior are neural signals from the digestive tract, nutrient signals related to energy stores and GI tract hormones (CCK, insulin, glucagon and ghrelin)
What is the most important long-term regulator of feeding behavior and appetite?
Leptin is the most important long-term regulator of feeding behavior and appetite
Which of the following contributes to a person’s BMR? Kidney function, breathing, jogging, eating, fever
Kidney function and breathing contributes to a person's BMR
Samantha is tall and slim, but athletic and well-toned. Her friend Ginger is short and stocky, bordering in obese, Which would be expected to have greater BMR, relatively speaking?
Samantha has a larger relative body surface area and therefore a higher BMR
What is the body’s core?
The body's core is the organs within the skull and thoracic and abdominal cavity
Cindy is flushed and her teeth are chattering even though her bedroom temperature is 72F. Why do you think this is happening?
Cindy’s body temperature is rising as heat promoting mechanisms (shivering, chills) are activated. Possible an infection has caused the hypothalamic temperature to be set higher (fever)
How does convection differ from conduction in causing heat loss?
Conduction is the transfer of heat from a warmer objects to a cooler one when the two are in direct contact with each other.
Convection is the process that occurs because warm air expands and rises and cool air, being denser, falls
List at least two reasons that metabolic rate declines in old age?
Two reasons that metabolic rate declines in old age are because muscle mass declines and physical activity tends to reduce.
List two types of drugs ot over-the-counter products that can interfere with the nutrition of elderly people?
Some drugs that can interfere with the nutrition of elderly antibiotics are some antibiotics that interfere with food digestion and absorption, alcohol and drugs that cause electrolyte imbalance