Ch. 19 Metabolism

What is the source of energy used to form ATP?

Carbohydrates, fats, proteins, or body tissue catabolism

How many kilocalories are provided by 1 gram of fat?

9 kilocalories

How is metabolic rate commonly measured?

Amount of heat generated or oxygen consumed per minute

What role does the hypothalamus play in body temperature regulation?

Corrects deviations by directing physiological responses

What best describes basal metabolic rate (BMR)?

O2 consumed by a relaxed, awake person at a comfortable temperature, 12–14 hours after eating

What is the general range of daily energy requirements for humans?

1,300 to 5,000 kcal/day

What is the average daily energy requirement for a male?

2,500 kcal/day

What is the definition of turnover rate?

The rate at which a particular molecule is broken down and resynthesized

What is the approximate daily turnover rate for protein?

150g/day

What is the approximate daily turnover rate for fat?

100g/day

Why are dietary requirements for most fatty acids and amino acids lower?

Because the body can produce most of them

How many essential amino acids are there?

9: lysine, tryptophan, phenylalanine, threonine, valine, methionine, leucine, isoleucine, and histidine

Which of the following are essential fatty acids?

Linoleic acid (omega-6) and linolenic acid (omega-3)

Which vitamins are made in small amounts by the body?

B, D, and K

Why must most vitamins be obtained from the diet?

The body cannot make them or only makes a small amount

What is the primary function of Vitamin E in the body?

Acts as a strong antioxidant and reduces inflammation

What is Vitamin K essential for?

Making clotting factors for blood coagulation

What are the functions of Vitamin D in the body?

Calcium absorption, tissue differentiation, and gene expression regulation

How is Vitamin D produced in the body?

Made by the skin when exposed to UV light

What are some roles of Vitamin A in the body?

Embryonic development, T cell activity, dim light vision, and epithelial cell function

What is the main function of Thiamine (Vitamin B1)?

Needed to convert pyruvate to acetyl CoA

Niacin (B3) and Riboflavin (B2) are essential for the production of which coenzymes?

FAD and NAD which acts as hydrogen carriers

What is the primary function of Pyridoxine (Vitamin B6)?

Amino acid metabolism

What is a key function of Vitamin C in the body?

Acts as an antioxidant that inactivates free radicals

What are minerals primarily used for in the body?

Serving as cofactors and supporting various physiological processes

What is the disease associated with a deficiency in Vitamin B1 (Thiamine)?

Beriberi and Wernicke-Korsakoff syndrome

A deficiency in Vitamin D can contribute to which of the following disorders?

Psoriasis and rickets

What is the result of an iodine deficiency?

Thyroid issues

What are free radicals?

Molecules with unpaired electrons

How do Vitamin C and Vitamin E help protect the body from oxidative stress?

By picking up unpaired electrons from free radicals

Which of the following is the preferred energy source for the brain?

Glucose

What is the preferred energy source for skeletal muscles at rest?

Fatty acids

What is gluconeogenesis?

the production of glucose from non carbohydrate molecules, including lactate and amino acids, primarily in the liver

What does the adipostat mechanism defend?

A set amount of adipose tissue

In what form is energy stored in white fat?

Triglycerides

What are adipokines?

Regulatory molecules secreted by adipocytes

What are the leading causes of diminished immune capacity worldwide?

Starvation and malnutrition

Leptin

prevents hunger

What causes strong stomach contractions that signal hunger?

Motilin

What is the role of neuropeptide Y (NPY) in the body?

It directly stimulates hunger

What triggers the secretion of ghrelin?

When the stomach is empty

Which hormones are secreted by enteroendocrine cells to suppress hunger following a meal?

Polypeptide YY (PYY) and Glucagon-like polypeptide-1 (GLP-1) (oxempic, mounjaro)

Which type of pancreatic cells secrete insulin?

Beta cells

What do alpha cells of the pancreas secrete?

Glucagon

Delta cells in the pancreas are responsible for secreting which hormone?

Somatostatin

What is one effect of glucagon on glucose uptake?

It prevents cellular uptake of glucose in skeletal muscle, liver, and adipose tissue

How does glucagon increase blood glucose levels?

By promoting conversion of glycogen to glucose and releasing it from the liver

What does glucagon do in adipose tissue?

Promotes release of fatty acids

What effect does the parasympathetic nervous system have during eating?

Stimulates insulin release

What is the result of catecholamine release during a fight-or-flight response?

Stress hyperglycemia

diabetes mellitus

characterized by chronic high blood glucose; results from inadequate secretion or action of insulin. second leading cause of blindness

type 1 diabetes

insulin-dependent diabetes, beta cells are destroyed and insulin is not made

Type 1 diabetes is associated with which part of the genome?

MHC on chromosome 6

type 2 diabetes

insulin-independent, most common (95%)

most widely used drug to treat type 2 diabetes

metformin (glucophage)

adrenal medulla

secretes catecholamines (epinephrine and norepinephrine) in response to sympathetic stimulation​

Adrenal cortex

secretes mineralocorticoids (aldosterone) and glucocorticoids (cortisol)​