Metabolic fuels and precursors EC Flashcards Preview

Evan's Step 1 Prep Material > Metabolic fuels and precursors EC > Flashcards

Flashcards in Metabolic fuels and precursors EC Deck (33):
1

Why are intracellular carbohydrates phosphorylated?

To keep them from diffusing out of the cell

2

Which isomer are most human sugars?

D isomer

3

What are reducing sugars?

Open chain forms that allow carbonyl group to react with reducing agents

4

Glucuronic acid

Reacts with unconjugated bilirubin to form conjugated
Component of GAGs (glycosaminoglycans)

5

Sorbital derived damage in diabetes

Lens (cataracts)
Schwann cells (peripheral neuropathy)
Pericytes (retinopathy)

6

Maltose

Glucose + Glucose

7

Lactose

Glucose + Galactose

8

Sucrose

Glucose + Fructose

9

Monosacharides

Glucose, Fructose, Ribose
"GFR"

10

Disaccharides

Maltose, Lactose, Sucrose
"MLS"

11

Essential fatty acids

Linoleic acid (18C)
Linolenic acid (18C)

12

Carnitine shuttle

Moves long chain fatty acids from cytosol to mitochondria

*deficiency results in nonketotic hypoglycemia*

13

Corticosteroids effect on phospholipids

Inhibit phospholipase A2, inhibit arachadonic acid release

14

Gly (glycine)

Smallest amino acid
Inhibitory neurotransmitter in spinal cord
Synthesis of heme
Abundant in collagen

15

Ala (alanine)

Alanine cycle during fasting: major substrate for gluconeogenesis

16

Val (valine)

Branched
Not degraded by liver
Used in muscle
Increased in maple syrup urine disease

17

Leu (leucine)

Branched
Not degraded in liver
Ketogenic
Used in muscle
Increased in maple syrup urine disease

18

Ile (isoleucine)

Branched
Not degraded by liver
Used in muscle
Increased in maple syrup urine disease

19

Met (methionine)

Polypeptide chain initiation
Methyl donor (as S-adenosylmethionine)

20

Pro (proline)

Helix breaker
Only a.a. with side chain cyclized to alpha amino group
Hydroxylation in collagen via ascorib acid
Binding site for collagen cross-bridges

21

Phe (phenylalanine)

Increased in PKU
Aromatic side chain (increased in hepatic coma)
Tyr>Dopa(malanin)>Dopamine>NE>Epi

22

Trp (tryptophan)

Precurser to serotonin, niacin, and melotonin
Aromatic side chains (increased in hepatic coma)

23

Cys (cysteine)

Forms disulphide bonds
Sensitive to oxidation
Component of glutathione (RBC antioxidation)
Deficient in G6PD deficiency

24

Ser (serine)

Single carbon donor
Phosphorylated by kinases

25

Thr (threonine)

Phosphorylated by kinases

26

Tyr (tyrosine)

Precursor to melatonin, catacholamines, and thyroid hormones
Phosphorylated by kinases
Aromatic side chain (increased in hepatic coma)
Must be supplied in PKU
Signal transduction (tyrosine kinase)

27

Asn (asparagine)

Insufficiently synthesized by neoplastic cells
Used to treat leukemia

28

Gln (glutamine)

Most abundant
Nitrogen carrier
NO donor in purine/pyrimidine synthesis
NH3 detox. in brain and liver
Fasting state: carries amino group from muscle to other tissue
Fasting state: fuel for kidneys, intestine, and immune system

29

Lys (lysine)

Basic
Ketogenic
Abundant in histones
Hydroxylation in collagen aided by ascorbic acid
Binding site for cross-bridges in protocollagen

30

Arg (arginine)

Basic
Essential for growth in children
Abundant in histones
Precursor to creatine, urea, & NO

31

His (histidine)

Basic: ZERO charge at pH=7.4
Physiologic buffer
Histamine precursor
Residue in Hg coordinated with heme
Essential for growth in children

32

Asp (aspartate)

Acidic
Forms oxaloacetate by transamination
Important for albumin binding properties

33

Glu (glutamate)

Acidic
Forms alpha-ketoglutarate by transamination
Important for binding properties of albumin
GABA and Glutathione precursor

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