Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FST2201 : Introduction to human nutrition > W6 : Carbohydrates > Flashcards

W6 : Carbohydrates Flashcards

1
Q

What are the 3 main types of carbohydrates and how many calories per gram do they contain?

A

1) SImple sugars (mono/dissacharides)
- 4 cal/g

2) Complex carbs (polysaccharide – amylose in starch)
- 4 cal/g

3) Dietary fibre (polysaccharide – cellulose)
- 2 cal/g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which simple sugar is the sweetest among all simple sugars?

A

Fructose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name the 3 disscharides and name the monosaccharides they are made up of

A
  • Maltose = glucose + glucose
  • Sucrose = glucose + fructose
  • Lactose = glucose + galactose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 3 main polysaccharides that serves as storage / structural components in humans and plants?

A
  • glycogen : storage form of glucose in muscle and liver cells
  • Starch (amylose + amylopectin) : storage form of glucose in plants
  • Cellulose: structural polysaccharide that gives strength to** plant cell walls**
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is meant by dietary fibres?

A

Part of plant material in the diet that resists enzymatic digestion, cannot be digested by humans.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What kinds of bonds are found in dietary fibre, such as cellulose?

A

β 1,4-glycosidic bonds which humans cannot digest since humans only have enzymes to hydrolyse α 1,4-glycosidic bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 2 kinds of fibre and what are their functions?

A
  1. Soluble fibre – substrates for gut microbiome
  2. Insoluble fibre – absorbs remaining water and salts to add bulk to stool.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are oligosacchardes and what is their function?

A

Sugars with** more than 2 **but < 10 monosaccharides linked together.
- oligosacchardes stimulate gut flora as they are food/substrates for gut microbes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What 2 kinds of sugars are used as substrates (food) for gut microflora?

A
  1. Soluble fibre
  2. Oligosaccharides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are polysaccharides? List 3 examples.

A
  • Sugars with many monosaccharides linked together
  • Starch, glycogen, fibre
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the definition of glycemic index?

A

A measure of how much blood glucose is raised by a 50g portion of carbohydrate containing food, compared to 50g of glucose or white bread.
- It is a number ranging from 0 to 100, with pure glucose given an arbitary value of 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is glycemic response?

A

How much blood glucose levels rise after consumption of a food (composite food) pr mea. (not restricted to only carbs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the difference between glycemic index and glycemic response?

A
  1. Amount of carbs – glycemic index requires 50g of available carbs (same amount), while glycemic response does not care about how much carbs are available
  2. Macronutrient – glycemic index is concerned with how much blood glucose rise by with 50g of avail carbs, while glycemic response measures how much blood glucose rises after a meal , may include other macronutrients like protein and fat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do high GI foods do to the blood glucose levels and hunger?

A

It causes a huge spike in blood glucose, and the response of insulin to the spike in glucose levels causes the blood glucose to decrease to more than baseline level of glucose
- this can increase hunger and increase snacking.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What values are :
1. Low glycemic index
2. Moderate glycemic index
3. High glycemic index

A
  • Low GI : <= 55
  • Moderate GI: 56-69
  • High GI : >=70
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

After digestion in the small intestine, how are monosaccharides absorbed and where do they travel to?

A
  • Monosaccharides enter the capillaries of intestinal villi
  • Monosaccharides travel to liver via portal veinor to muscle cells for utilisation or storage of glucose as glycogen
17
Q

why is glucose metabolism/homeostatis important?

A

Glucose is used as a key source of energy for certain cells – esp brain, nerve cells, red blood cells which only use glucose as source of energy and cannot use fat/protein as a source of energy, unlike muscle cells

18
Q

Decribe carbohydrate digestion in the :
1. Mouth
2. Stomach
3. Small intestine
4. Large intestine

A

1) Mouth : where amylase breaks down starch

2) Stomach : Little carb digestion, but presence of fibre slows down digestion, extending the feeling of fullness

3) Small intestine : Most carb digestion takes place here
- Pancreatic amylase, specific disaccharide enzymes (lactase, sucrase,maltase)
- All carbs broken down into simple sugars

4) Large intestine : Soluble fibre digested by gut microbes

19
Q

Is a high or low glycemic response desired?

A

Low glycemic response is desired as this means spike and drop in blood glucose may not be as sharp (so energy levels are maintained throughout the day)

20
Q

What are 2 main differences between glycemic response of a person and glycemic index of a food?

A
  1. Glycemic index measures the relative change in blood glucose with a fixed portion of available carbohydrates (50g), while glycemic response measures the relative change in blood glucose in a person without specifying the amount of available carbohydrates.
  2. Measurement of GI is confined to carbohydrate containing food only, while glycemic response is not confined to only carbohydrate containing food.(can be a meal or composite food containing proteins etc)
21
Q

What is meant gluconeogenesis?

A

Synthesis of glucose from non-carbohydrate sources

22
Q

What are the 2 main hormones in glucose metabolism and their functions?

A
  1. Insulin : stimulates glucose absorption into cells and conversion to glycogen in liver and muscle cells when glucose concentration is high
  2. Glucagon : stimulates breakdown of glycogen (glycogenesis) in liver into glucose, releasing into bloodstream when blood glucose is low
23
Q

What is the difference between glucose storage in the liver and in the muscles?

A
  • Liver storage : glucose condenses to form glycogen and glucose is hydrolysed and transported to the rest of the body when needed
  • Muscle storage : glucose is released for muscle use only
24
Q

Glucose is stored in the ____ and ____ as ____

A

Liver, muscles, glycogen

25
Q

Controversies with carbs

As people increased carb % in their diets, there is also a rise in obesity due to excess calories. Where do the excess calories come from? [2]

A
  1. Intake of more simple sugars (HFCS and sucrose)
  2. Simple sugar intake is mostly from foods containing added sugar, which are not nutrient dense (high calories, low nutrient)
26
Q

Controversies with carbs

Carbohydrates causes obesity. True or False?

A

False, thoughthere is a correlation between increased % carb intake (meal composition) and obesity, BUT daily energy intakes also increased and activity levels have declined –> meaning that the excess calories caused the increase in body weight and lead to obesity
-and excess calories is due to consumption of simple sugars in the form of added sugars in non-nutrient dense foods

27
Q

Controversies with carbs

What is the difference between high fructose corn syrup and sucrose?

A

Sucrose : a dissacharide made of fructose and glucose chemically combined together
-50% glucose + 50% sucrose when hydrolysed, present in 1:1 ratio

High fructose corn syrup (HFCS) : mixture of 2 monosaccharides
- 55% fructose and 45% glucose (not chemically bonded)

28
Q

What are some limitations of glycemic index? [5]

A
  1. Does not consider portion size – glycemic index is only based on 50g of available carbohydrates but people usually eat different amounts
  2. Does not consider meal composition – Combining different carbohydrate foods with different GIs, or adding protein and fat, changes the overall GI of a meal.
  3. Does not consider individual variation – glycemic response to the same food varies between different people. For the same person, glycemic response can vary from day to day or throughout the day.
  4. Does not consider nutrition – The GI doesn’t provide other nutritional information. For example, cantaloupe has a medium to high GI but is a good source of nutrients, while whole milk has a low GI but is high in calories and fat.
  5. Reported GI may not be representative of an individual’s true glycaemic response to a carbohydrate-based food / carbohydrate-based meal.
29
Q

What are some factors affecting a person’s glycaemic response to food?

A
  1. Food structure / matrix
  2. Meal macronutrients
  3. Time of meal
  4. Genetics
  5. Gut microbiome
30
Q

What is the Dietary Reference Intake (DRI) of carbs?

A

45-65% of total energy

31
Q

What is the Recommended Dietary Allowance (RDA, enough for 98%) for carbohydrates?

A

130g per day

32
Q

What is the Dietary Reference Intake (DRI) of fibre? Is there upper limit for fibre?

Hint: mass

A

14g per 1000 kcal.
No UL

FST2201 : Introduction to human nutrition (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions