Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Human Nutrition > Carbohydrates > Flashcards

Carbohydrates Flashcards

(60 cards)

Start Studying
1
Q

What percentage of the energy in our diet does carb make up?

A

45-65% total calories

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

What are carbs made of?

A

Carbon
Hydrogen
Oxygen

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

How can simple carbs be classified?

A

Monosaccharide (one sugar)
Disaccharide (two sugars)
Oligosaccharide (more than 3, less than 10)
Polysaccharide (more than 10)

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

What are the 3 monosaccharides?

A

Glucose
Fructose
Galactose

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

What are the 3 disaccharides

A

Maltose
Sucrose
Lactose

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

What are the 3 complex carbs?

A

Starch
Glycogen
Fiber

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

What is glucose commonly known as?

A

Blood sugar
Essential energy source for all body’s activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is fructose?

A

Sweetest sugar
Occurs naturally in fruits
In desserts/soft drinks, etc

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

Does galactose naturally occur in foods?

A

No, rarely as a single sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do disaccharides form?

A

Putting together two monosaccharides through condensation (water removed)

Hydrolysis (water added) will cause them to seperate again

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is maltose made of

A

2 glucose

Produced when starch breaks down (human digestion of carbs, fermenting alcohol)

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

what is sucrose?

A

One fructose, one glucose

Table sugar

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

What is lactose?

A

Galactose and glucose

Principle carb of milk/milk products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How much should complex carbs form your plate

A

50%, should be the majority of what you eat

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

What is glycogen?

A

Human body stores glucose unit as glycogen in highly branched chains

Arrangement permits rapid hydrolysis

Can only store 24hrs of it

Found in limited meats, not plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How is glucose released?

A

When message to release energy arrives as glycogen storage sites (liver, muscles), enzymes respond by attacking branches to make surge of glucose avaliable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a starch?

A

Long chains of thousands of glucose molecules linked, stored in plant cells

Molecules packed side by side, body hydrolyses into glucose for energy

Wheat, grains, rice, tubers, root crops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the difference between an alpha and beta bond starch?

A

Alpha - easily digested (amylose)

Beta - are not broken down (amylopectin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is dietary fibre made of?

A

Non-starch polysaccharides - cannot be broken down by enzymes in body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the difference between soluble and insoluble fibre

A

Soluble - dissolves in water to forms a gel, lowers blood cholesterol, fermentable in colon, balances blood sugar levels, lowers risk of diabetes, satiety

Insoluble - fibres that do not dissolve in water, not very fermentable, adds bulk and soften stools, alleviates constipation and increases transit time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are resistant starches and where are they found?

A

Starch that escapes digestion and can be fermented by bacteria to produce short chain fatty acids

  • physically enclose (trapped) starch, found on coarse
  • un-gelatinised (uncooked) starch (raw potatoes, green bananas)
  • retrograded amylose (starch polymers) form after starchy foods have been cooked and left to cool
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is physic acid?

A

Found accompanying dietry fibre

Close bonds make it impossible to determine whether dietary fibre, physic acid or both that binds with minerals, preventing their absorption

Binding - risk of mineral deficiency, lessened if fibre/mineral intake is reasonable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the goal of carb digestion?

A

Breaking down sugars and starches into small molecules (chiefly glucose) for body to absorb and use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What happens in the mouth in carb digestion?

A

Salivary enzyme (amylase) hydrolysis starch to shorter polysaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What happens in the stomach in digestion?
Stalled bolus mixes with stomach acid and enzymes, inactive salivary amylase Dietary fibre lingers in stomach, delays gastric emptying (satiety) Stomach acid doesn’t contain enzymes to digest carbs
26
What happens in the small intestine in carb digestion?
Major carb-digestive enzyme - pancreatic amylase - enters via pancreatic duct Breaks down polysaccharides to shorter glucose chains and maltose Goes to outer membranes of intestinal walls, where specific enzymes break down specific disaccharides
27
What enzymes does maltese, sucrose and lactase break down?
Maltese - Breaks maltose into two glucose molecules Sucrose - breaks sucrose into one glucose and one fructose molecule Lactase - breaks lactose into one glucose and one galactose molecule
28
What happens in the large intestine during carb digestion?
Dietary fibre remains in tract, attracting water, which softens stool for passge Bacteria in GI tract also ferment some dietary fibre (forms water, gas, short-chain fatty acids) Colon uses these fat molecules for energy between 1-4 hours after meal, mostly digested
29
How are glucose and galactose absorbed?
Glucose and galactose - traverses cell linking of small intestine by active transport Requires energy in form of ATP - transport protein is loaded with sodium, then glucose/galactose
30
How is fructose absorbed?
Absorbed by facilitated diffusion, which slows entry and produces smaller rise in blood glucose. It is ‘passive’ absorption
31
How are carbs digested?
Unbranched chains of starch are digested slowly, place for enzymes to attack and release glucose fast As blood from intestines circulated to lover, cells there take fructose and galactose and convert them (often to glucose)
32
What is occurring in lactose intolerance?
Intestinal cells do not produce enough lactase (enzyme) to ensure disaccharides are digested and absorbed effectively When more lactose is consumed than what lactase can handle, molecules remain undigested. Attracts water - causes abdominal discomfort and diarrhoea Undigested lactose becomes food for intestinal bacteria, which multiplies and produces irritating acid and gas
33
What is the role of glucose in the body?
glucose is the main source of energy for the central nervous system Plays central role in carb metabolism
34
How is glucose stored?
Stored as glycogen in liver, can release glucose into bloodstream when needed Also stored in muscle cells - used mainly for exercise Brain - emergency supply
35
What happens when blood glucose rises?
Liver cells link excess glucose molecules into long branching chains of glycogen Happens after a meal
36
What happens when blood glucose falls?
Liver cells break glycogen by hydrolysis reactions into single molecules of glucose, releasing them into bloodstream
37
Why can glycogen only be stored for short periods of time?
Because it holds water, is therefore bulky and cannot be stored in excess Long-term energy uses abundant, water-free fat
38
How is glucose broken down for energy?
Enzymes in cell breaks glucose down to carbon dioxide and water
39
What is gluconeogenesis?
When glycogen stores become depleted, the body makes glucose from protein
40
What is protein sparing?
The role of carbs - having an adequate amount of glucose in diet so protein can be stored
41
How are ketone bodies made?
If less glucose than required for brain’s energy, fat fragments combine Ketone bodies provide alternative fuel source during starvation When production exceeds their use, accumulates in blood (called ketosis, disturbing acid-base balance)
42
How does fat get made from glucose?
After meeting energy needs and filling glycogen stores, body stores the rest as fat Liver forms glycerol (triglyceride) Fat travels to fatty tissues for storage
43
How does the body maintain glucose homeostasis?
Homeostasis: body must maintain blood glucose within limits that permit cells to nourish themselves If glucose falls - dizzy and weak If glucose rises - fatigued Regulated by two hormones from pancreas: insulin and glucagon
44
How does insulin work?
When blood glucose rises (after meal) pancreas respond by secreting insulin into blood Insulin contacts receptors to move glucose from blood into cells, or conversion into fat
45
How does glucagon work?
When blood glucose falls, pancreas secrete glucagon into blood. Signals to liver to break down glycogen stores to release glucose into blood
46
Why does adrenaline release glucose?
Adrenaline (fight or flight) signals liver to release glucose, to ensure body has energy to fuel emergencies
47
Why do complex carbs delay insulin response?
Carbs that digest slowly prolong the presence of foods in the digestive tract, providing greater satiety
48
What does epinephrine do?
Acts quickly to bring glucose out of storage during times of stress
49
What is diabetes?
When blood glucose surges after meal, remains above normal levels as insulin is either inadequate or ineffective
50
What is the difference between type 1 and type 2 diabetes?
type 1 - pancreas fail to produce insulin (genetic predisposition) Type 2 - cells fail to respond to insulin (consequence of obesity)
51
What is hypoglycaemia?
When blood glucose falls below normal Consequence of poorly managed diet - too much insulin, strenuous physical activity, inadequate food intake of illness Results in weakness, anxiety, hunger, trembling
52
What is the glycemic response?
How quickly glucose is absorbed after a person eats, how high blood glucose rises and how quickly it returns to normal
53
Is a low or high glycaemic response required?
Low: slow absorption, modest rise, smooth return to normal
54
What is the glycemic index?
Classifying food according to their potential to raise blood glucose Low GI foods also manage blood lipids to lower risk of heart disease
55
What is a low, medium and high GI?
Low <55 Medium 56-69 High 70>
56
What are some health effects caused by sugar?
- Obesity/chronic disease - nutrient deficiencies (supplies energy without nutrients) - dental caries/tooth decay
57
What are some alternative sweeteners?
Artificial sweeteners (no energy) Herbal product (stevia) Sugar alcohols (occurs naturally, bulk and sweetness)
58
How many kj (out of 8000) of calories should a person have a day?
3600-5200kj a day 200-325g (dietary fibre 25-30g)
59
What are the positive impacts of dietary fibre?
Fosters weight management Lowers blood cholesterol Enhances health of GI Protects heart disease Prevent colon cancer, diabetes, haemorrhoids, etc.
60
What occurs with excessive intake of dietary fibre?
Displaces energy and nutrient-dense foods Causes intestinal discomfort and distension May interfere with mineral absorption

Human Nutrition (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions