Metabolism + Nutrition
What are the three main macronutrients?
Proteins
Lipids
Carbohydrates
How many calories are there per gram of carbohydrate?
4 kcal per gram
What is the main functional unit of the kidney?
The nephron
At the most simplistic level, what are the primary organs of the urinary system?
Kidneys
Ureters
Bladder
Urethra
Name the five primary electrolytes
Sodium
Potassium
Magnesium
Calcium
Chloride
What are the three areas of the body's glucose pool?
As glucose in the blood, and as glycogen in liver, and skeletal muscle
What is the metabolic process that involves the breakdown of glucose for energy?
Glycolysis
What is the primary function of the renal corpuscle and which two structures are housed within?
Bowman's capsule and the glomerulus are primarily concerned with filtration
List three functions of the urinary system
Urine elimination
Regulate blood volume and pressure
Control electrolyte/metabolite levels
Regulate blood pH
Contributes to RBC production (EPO release from kidneys)
Helps synthesise calcitriol (Vit D)
Define electrolyte
Substance that conducts electricity through the movement of ions
What is the difference between an anabolic reaction and a catabolic reaction?
Anabolism uses energy to combine parts into a larger whole (i.e. amino acids come together to form proteins). Catabolic reactions break down a larger molecule into component parts and release energy
What is the body's primary insulin dependent transporter? What stimulates the movement of these transporters to the cell membrane?
GLUT-4
Stimulated by insulin and Ca2+ ions
What is the primary reason for the osmotic gradient generated in the loop of Henle?
Helps concentrate urine by driving water out of the collecting duct
What is the process of waste removal of blood in those whose kidneys no longer function properly?
Dialysis
Describe why many sports drinks have pros and cons. Why is context important?
Sugar consumption (pro or con depending on context), do you need electrolytes if you are not sweating heavily? etc.
What does hexokinase do in glycolysis?
Turns glucose into glucose-6-phosphate (G6P)
What is the major rate limiting step of glycolysis?
Phosphofructokinase (PFK)
Which compound is released by the kidneys in the RAAS system? What does this do?
Kidneys release renin which converts angiotensinogen into angiotensin I
Which two major waste products are key signs of kidney function?
Creatinine and urea
Describe respiratory compensation
Increasing or decreasing inhalation or exhalation can lead to alterations in pH
Acidosis: pH < 7.35
Chemoreceptors sense a change in pH
Brainstem respiratory centers increase ventilation (hyperventilation) to breathe off excess CO2 and stop the production of excess H+ ions
Alkalosis: pH > 7.45
Hypoventilation to produce more CO2 and increase H+ ion production to bring pH back down
Describe the role of NAD+ and FAD
NAD+ (Nicotinamide Adenine Dinucleotide) and FAD (Flavin Adenine Dinucleotide) are vital coenzymes involved in cellular respiration
Both are key electron transporters that carry energy to the electron transport chain
Which two enzymes facilitate the conversion of pyruvate into either Acetyl-CoA or Lactate?
PDH converts pyruvate into Acetyl-CoA and LDH converts pyruvate into Lactate
Describe the RAAS system - stimuli, receptors, chemical release/conversion, and response
See slide 13 on 4/17 lecture slides
Describe the flow of urine through the kidney and to the urethra in order using the following terms:
Papillary duct
Urinary bladder
Distal convoluted tubule
Renal corpuscle
Urethra
Loop of Henle
Renal cortex
Major calyx
Collecting duct
Renal pelvis
Ureter
Nephron
Renal pyramid
Proximal convoluted tubule
Fibrous capsule
Minor calyx
Fibrous capsule, renal cortex, renal pyramid, nephron, renal corpuscle, PCT, loop of henle, DCT, collecting duct, papillary duct, minor calyx, major calyx, renal pelvis, ureters, urinary bladder, urethra
What is the primary role of the bicarbonate buffer system? Write out the chemical equation
This system combines water and CO2 to create carbonic acid which dissociates into bicarbonate and H+
Carbonic acid is a weak acid and helps buffer alakine blood while bicarbonate is a weak base and helps to buffer acidic blood
H2O + CO2 - H2CO3 - HCO3 + H+