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Flashcards in Carbohydrates Deck (63)
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1

An aldehyde, ketone, or a compound that yields either aldehyde or ketone after hydrolysis

Carbohydrates

(*Phil setting: based on response of body based on insulin levels)

2

General formula of monosaccharide

CnH2nOn

3

Aldoses and ketoses are

monosaccharides

4

Classifications of carbohydrates based on conromation

D and L Monosaccharides/
Fischer Projection
Haworth Projection

5

basis of fischer projetion

position of OH group (D or L)
*alpha-below beta-above (Haworth)

6

In the Embden-Meyerhoff Pathway, Glyceraldehyde-3-Phosphate is converted to?

Dihydroxyacetonephosphate (DHAP) or continue to the
Kreb’s Cycle

7

Glycolysis converts glucose to

pyruvate

*If body does not need sugar, glucose is shunted to PPP and etc

8

hormones from pancreatic beta cells (I of L) in fed state

insulin

*promotes cellular uptake of glucose (allowing transport of sugars from blood; anabolic)

9

How is proinsulin converted to insulin?

removal of C peptide (proinsulin: a + b + c peptides)

10

What are the requirements for insulin release?

− Glucose
− Other amino acids that can ramp up release of insulin
(Leucine, Arginine, Histidine, Phenylalanine)
− Sulfonylureas (tolbutamides)
− ACTH, GH
o As ACTH increases, cortisol increases which leads to an increase in glycolysis

11

What causes release inhibition of insulin?

− Thiazide diuretics (hypertensive drug)
− Dilantin (antiseizure)
− Human placental lactogen (diabetes of pregnancy)

12

What causes decreased tissue response to insulin?

− Glucocorticoids (Obesity)
− Estrogens (Inactivity)
− Progestins (Low carbohydrate diet)

13

Insulin INCREASES these metabolic pathways

lipogenesis
protein synthesis
glycogenesis

14

Insulin DECREASES these metabolic pathways

lipolysis
ketone formation
gluconeogenesis
glycogenolysis

15

hormones involved in unfed/fasting state

glucagon (from pancreatic alpha cells; catabolic)

16

What happens to glycogen in the liver? muscle?

liver: glycogen is converted to glucose, and released into the blood
Muscle: glycogen converted to glucose-6-phosphate, and remains in the muscle for its own energy needs

17

Its action is similar to glucagon and it is immediately expended

“Fight or Flight” epinephrine from adrenal medulla

18

Hormones involved in gluconeogenesis

cortisol (hydrocortisone)- from adrenal cortex; inhibits glucose entry to muscle, connective and lymphoid tissue
Adrenocorticotropic Hormone (ACTH)- from anterior pituitary gland and stimulates prod of cortisol

19

Cortisols stimulates release of

gluconeogenic amino acids from the muscles
*also promotes conversion of amino acids into glucose by liver

20

What does cortisol stimulate in adipose cells?

lipolysis by releasing glycerol for conversion to glucose by liver

21

T or F: glycolysis stops in the sample once it is drawn

false
*Serum/plasma must be separated from cells soon after collection to avoid a falsely decreased glucose result
→ Ideally, processing must be done within 1 hour

22

What are the conditions of glucose reabsorption and glycosuria in PCT?
(renal threshold)

→ Reabsorbs all glucose if <180 mg/dL
→ Glycosuria results if blood glucose >180mg/dL
* >600 mg/dL in the kidney: greater than blood glucose threshold because of countercurrent mechanism

23

Increase in plasma glucose levels due to hormone imbalance

hyperglycemia

24

glucose reference ranges

74-106 mg/dL
increased if >110-120 mg/dL

25

Why does blood sugar increase at night?

fasting blood sugar (body undergoes gluconeogenesis at night to supply energy for the body's organs)

26

How is fasting blood sugar counteracted?

insulin production so glucose enters cells and cortisol becomes active (basal metabolic rate) to increase blood sugar

27

fasting blood sugar can have this effect on diabetics

somogyi effect

28

Why shouldnt diabetics* take extra insulin shots before sleeping?

*in a constant catabolic state

Blood sugar goes down over the course of the night leading to hypoglycemia and a surge in cortisol from 4am-6am leads to hyperglycemia rebound leading to diabetic coma

29

Immediate effects of hyperglycemia

increased extracellular osmotic pressure (increased glucose in plasma = water out of cells; dehydration)
acidosis (respiratory > metabolic)

30

[Hyperglycemia effects] Results if glucos remains uncontrolled

acidosis
(If patient's cells are not able to take in glucose, fats are converted to fatty acids = keto acids)