EXAM III Final Flashcards
How many high energy phosphate bonds are needed to form one peptide linkage?
1 2 3 4 5
4 = (48,000 cal) total
With each peptide bond storing 500-5000 cal
Not an effective way of storing up energy
What type of linkages is among the most important intracellular processes that require energy?
Peptide linkages
What are the two steps of the ornithine cycle that occur in the mitochondria?
2NH3 (ammonia) + 1CO2 –> Carbamoyl Phosphate
Carbamoyl Phosphate + Ornithine —> Citrulline
What is the rate limiting factor for energy metabolism in the body?
ADP
Chemical rxns that depend on ADP as a substrate is very slow
Overall rate of a series of chemical rxns is determined by _______
Slowest step in the series; factor = ADP
What stimuli is one of the best known stimuli for increasing the rate of thyroid stimulating hormone (TSH)?
Cold
What are the 9 factors that influence metabolic rate?
- Arousal vs. Sleep
- Skeletal muscle
- Age
- Thyroid activity
- Testosterone
- Growth hormone
- Fever
- Sleep
- Malnutrition
Which state is more lethargic, hypothyroidism or hyperthyroidism?
Hypothyroidism
Liver has (high/low) blood flow and (high/low) vascular resistance
High blood flow and low vascular resistance
What percentage of resting cardiac output does the liver supply?
27%
Portal pressure into the liver ________, pressure from the liver to vena cava ________
9 mmHg, 0 mmHg
What is the effect of clot blocking of the portal vein or a major branch?
Blockage of return of blood from spleen and intestines
Increase in capillary pressure in the intestinal wall = loss of fluid = death
Ascites is a result of, due to what?
Large amount of fluid in the abdominal cavity as a result of higher than normal pressure in the hepatic veins
Back pressure causes fluid to flow into lymph, fluid leaks into abdominal cavity
T/F; hepatic sinusoids are highly permeable to proteins
True; efferent lymph [protein] = 6 g/dl (almost equivalent to [plasma])
List the 4 components of bile
- Bile acids - cholic and chenodeoxycholic acids via hepatocytes; deoxycholic acid & lithocholic acid
- Water and electrolytes
- Cholesterol and phospholipids
- Pigments and organic molecules = bilirubin
What converts heme into biliverdin?
Heme oxygenase
What are the factors of metabolic syndrome? (6)
- Obesity
- Insulin resistance
- Fasting hyperglycemia
- Increased lipid TGs
- Decreased HDL levels
- Hypertension
Insulin inactivates _______ and activates _____ in order for glucose uptake in the liver
Inactivates = phosphorylase
Activates = glucokinase
In order to P glucose to trap it into the liver
Under what conditions may down regulation of receptors occur?
- Inactivation of some of the intracellular protein signaling molecules
- Temporary sequestration of the receptor inside the cell
- Inactivation of some of the receptor molecules
- Destruction of receptors via lysosomes after internalized
- Decreased production of receptors
Under what conditions may UP regulation of receptors occur?
- When the stimulating hormone induces greater than normal formation of receptor or intracellular signaling molecules
- When the stimulating hormone may induce greater availability of the receptor for interaction with the hormone
List the 4 types of intracellular receptors for lipid soluble hormones
ATVR(ecks)
- Adrenal and steroidal hormones
- Thyroid hormones
- Vitamin D
- Retinoid hormones
Where on the DNA does the activated hormone-receptor complex bind to and what is this termed?
Promoter sequence of DNA
= Hormone response element
Calcium entry may be initiated by changes in membrane potential that open calcium channels or hormone interacting with membrane receptors that open calcium channels, once calcium entry occurs, where does calcium bind to?
Calmodulin
3-4 binding sites are filled and protein kinases are activated as well as inhibited
List the 5 types of cells of the anterior pituitary/adenohypophysis and give an example of each
- Somatotropes/acidophils = human growth factor
- Corticotropes = ACTH
- Thyrotropes = TSH
- Gonadotropes = LH & FSH
- Lactotropes = Prolactin
How many mg of iodine are required each year? Where is it absorbed?
50mg; absorbed via gut tract
What pump transports iodide from the blood in the basolateral side into the cell?
How much can iodide be concentrated in the cell?
Sodium-iodine symporter (2:1) in basal membrane of thyroid cell to put towards apical side
Energy via Na+/K+ ATPase pump
[30-250x]
What protein is important in transporting iodide across the apical membrane of thyroid cells into follicles?
PENDRIN
via Cl-Iodide counter-transporter
What enzyme converts iodide into iodine?
Peroxidase
What amino acid is involved in organifying iodine on thyroglobulin, forming T3 and T4?
Tyrosine
What hormone controls cortisol secretion?
LH
Aldosterone
ACTH
FSH
ACTH; via anterior pituitary
Which of the following is the major mineralocorticoid?
Catecholamines
Androgens
Cortisol
Aldosterone
Aldosterone; via Zona Glomerulosa (adrenal gland)
Which hormone has a major function of affecting electrolytes; Na+ and K+?
Catecholamines
Androgens
Cortisol
Aldosterone
Aldosterone
Which hormone secretion is mainly controlled by angiotensin II and K+?
Catecholamines
Androgens
Cortisol
Aldosterone
Aldosterone
Which of the following hormones increases Na+ reabsorption by kidney tubules, whose secretion is increased by hyperkalemia, and increases hydrogen ion secretion by kidneys?
Catecholamines
Androgens
Cortisol
Aldosterone
Aldosterone
Which of the following is the function of glucocorticoids?
a. Reduce stress
b. Stimulation of gluconeogenesis
c. Resists inflammation
d. Decrease glucose utilization by cells
e. May lead to adrenal diabetes
f. All of the above
All of the above
Which hormone is the major glucocorticoid?
Catecholamines
Androgens
Cortisol
Aldosterone
Cortisol; stress response
Which layer of the adrenal cortex secretes cortisol?
Medulla Zona reticularis Zona fasciculata Zona glomerulose All of the above
Zone Fasciculata
Which of the following is NOT a function of glucocorticoids
a. Decreases protein catabolism
b. Decreases glucose utilization by cells
c. Increases lipolysis
d. Resists stress
e. Resists inflammation
Decreases protein catabolism
List the 6 main functions of glucocorticoids
- Stimulates gluconeogenesis
- May lead to adrenal diabetes
- Resists stress & inflammation
- Resolution of inflammation
- Inhibits immune response
- Maintains vascular response to catecholamines