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1st year - Nutrition I > Carbohydrates > Flashcards

Flashcards in Carbohydrates Deck (16)
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1
Q

List the simple carbohydrates and describe their dietary importance

A

Monosaccharides:

Disaccharides:

2
Q

List the complex carbohydrates and describe their dietary importance

A

Oligosaccharides:

Polysaccharides:

3
Q

Explain why glucose is an essential nutrient

A

Glucose is used for glycogenesis, lipogenesis,synthesis of non-essential amino acids and it’s oxidized for energy production.

4
Q

Describe the digestion of carbohydrates

A

Monosaccharides: no digestion required

Starches:
Small intestine - major, mouth and stomach - minor
Alpha-amylase
- secreted by salivary glands and pancreas
- hydrolyzes alpha-1,4 linkages from glucose, maltose and isomaltose

Dissacharidases

  • active in microvilli of enterocytes
  • sucrase splits sucrose
  • lactase splits lactose
  • maltase splits maltose
  • isomaltase splits isomaltose (alpha-1,6 linkage)
5
Q

Describe the absorption and transport of carbohydrates

A

Glucose and galactose:
Into blood: facilitated diffusion (GLUT2)
Into cell: active transport (SGLT1) and facilitated diffusion (GLUT4)

Fructose:
Into blood: facilitated diffusion (GLUT2)
Into cell: facilitated diffusion (GLUT5)

6
Q

Describe the storage of carbohydrates

A

Glycogen

7
Q

Describe the metabolism of carbohydrates

A
Glycogenesis - conversion of glucose into glycogen for quick storage
Glycogenolysis - breakdown of glycogen to glucose during times of high energy demand
Glycolysis - break down of glucose to pyruvate
Gluconeogenesis - reverse of glycolytic pathway, synthesis of glucose from non-CHO precursor
Trcarboxilic acid (TCA) cycle - accounts for 90% of energy released from food, ATP produced from complete glucose oxidation,
8
Q

List some food sources of carbohydrates

A

Grains, tubers, legumes, some fruits & veggies

All carbohydrates are sourced from the sun - photosynthesis

9
Q

Discuss carbohydrates and dental health

A

Streptococcus mutans produce acids from sugars (glucose, fructose, lactose, sucrose & maltose).
Acids cause tooth decay.

Sucrose can be converted into polysaccharides, called dextrans, which stick to the tooth and form plaque that attracts sugars

10
Q

Define glycemic index and glycemic load

A

Glycemic index: increase in blood glucose during a two hour period after consumption of a certain amount of CHO compared with equal CHO from reference food.

Glycemic load: GI x g of CHO in one serving of the articular food.

11
Q

D-ribose is a component of what in all living cells?

A

RNA
DNA
ATP

12
Q

Why are clinical applications of D-ribose?

A

Heart disease
ATP deficiency in muscle related disease
Sports medicine - extended endurance, improved muscle recovery

13
Q

What are cautions when supplementing D-ribose?

A

May cause mild hypoglycemic effect

May cause increase in uric acid levels

14
Q

When would one use D-mannose clinically?

A

E. coli positive UTI

15
Q

What are adverse effects of consuming refined sugars?

A

They’re empty calories
Dysglycemia & dysinsulinism
Increased cardiovascular disease risk factors
- increased TGs, decreased LDL, increased BP, increased platelet adhesiveness
- decreased immune function
- diarrhea, gas and bloating and other GI symptoms

16
Q

Discuss xylitol, it’s benefits and when it is used

A

A sugar alcohol - tastes sweet
No caloric intake

Clinical indication

  • cavity prevention and treatment
    • streptococcus mutans can’t metabolize it
    • most important during pregnancy and during tooth development