Brainscape's Knowledge GenomeTM

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


See full index

home economics > carbohydrates > Flashcards

carbohydrates Flashcards

1
Q

what is photosynthesis

A

is the process by which green plants use sunlight to make sugar from carbon dioxide and water

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

how does photosynthesis occur

A

-plant roots absorb water (H20) from the soil
-leaves take in carbon dioxide (CO2) from the air
-Chlorophyll in leaves absorb energy from the sun

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

what is the end result of photosynthesis

A

-glucose is formed
-oxygen is released into the air

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

what is the equation for photosynthesis

A

6CO2 + 6H2O → C6H12O6 + 6O2

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

what is the elemental composition of carbohydrates

A

carbon, hydrogen, oxygen

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

what are monosaccharides

A

one sugar molecule. it is the smallest unit of a carbohydrate

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

what is the chemical formula for monosaccharides

A

C6H12O6

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

give examples and sources of monosaccharides

A

glucose- fruit
fructose- fruit and honey
galactose- digested milk

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

what are disaccharides

A

two sugar molecules joined together

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

what is the chemical formula of disaccharides

A

C12 H22 O11

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

give examples and sources of disaccharides

A

maltose- barley
sucrose- table sugar
lactose- milk

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

what are polysaccharides

A

many sugar molecules joined together

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

what is the chemical formula for polysaccharides

A

(C6H1005)n

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

give examples and sources of polysaccharides

A

starch- cereals and potatoes
glycogen- meat
cellulose- skins of fruits and vegetables

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

what are the properties of sugars

A

solubility, sweetness, assist aeration, maillard reaction, caramelisation, crystallisation, hydrolysis and inversion

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

explain solubility as a property of sugar

A

sugar is a white crystalline compound. it is a soluble in water. a syrup is formed when a large amount of sugar is dissolved in a small amount of water, e.g. canned peaches

17
Q

explain sweetness as a property of sugar

A

all sugars are sweet and give an appetising flavour to food. some sugars are much sweeter than others. this is measured on a point scale of sweetness, e.g. shortbread

18
Q

explain assists aeration as a property of sugar

A

Aeration occurs when sugar is whisked with an egg, denatured egg protein unfolds, entraps air bubbles, and creates heat, causing the egg to coagulate and form a permanent foam, e.g. sponges

19
Q

explain maillard reaction as a property of sugar

A

The maillard reaction is a non-enzymic browning process in food, resulting from the reaction between certain amino acids and sugars under dry heat. it produces an attractive brown colour and an appetising flavour, e.g. roast meat

20
Q

explain caramelisation as a property of sugar

A

on heating, sugar melts and caramelises. this occurs over ten gradual stages between 104C and 177C. caramelisation normally occurs at 160C, resulting in an attractive brown colour and a sweet taste. if overheated caramel will carbonise or burn, e.g. crème caramel

21
Q

explain crystallisation as a property of sugar

A

when a liquid has dissolved as much sugar as it can, it is saturated. if more sugar is added, crystals of sugar form in the solution and solidify when cooled, e.g. fudged

22
Q

explain hydrolysis as a property of sugar

A

hydrolysis occurs during digestion. water and enzymes split disaccharides into two monosaccharides into glucose and galactose

23
Q

explain inversion as a property of sugar

A

occurs when a liquid solution is heated in the presence of an acid or enzyme, causing the sucrose to split into glucose and fructose, e.g. jam-making

24
Q

what are the properties of starch

A

solubility, flavour, hygroscopy, hydrolysis,

25
Q

explain solubility as a property of starch

A

starch is a white non-crystalline powder. it is insoluble in cold water

26
Q

explain flavour as a property of starch

A

starch is not sweet in flavour

27
Q

explain hygroscopy as a property of starch

A

starch absorbs moisture from the air. this can cause uncovered foods, e.g. biscuits to soften and lose crunch

28
Q

explain dextrinisation as a property of starch

A

when dry heat is added to starch-based foods, dextrins are formed. this causes a colour change on the surface of the food, resulting in an attractive brown appearance

28
Q

explain gelatinisation as a property of starch

A

when starch is combined with liquid and heated to 55-70 the grains swell, burst and absorb the liquid around them, increasing the viscosity. as the temperature increases it becomes even more viscous and forms a sol. when the mixture cools, water molecules become trapped resulting in a gel, e.g. roux sauce

29
Q

explain hydrolysis as a property of starch

A

hydrolysis occurs during digestion. water and enzymes split starch into the disaccharide maltose

30
Q

what are the properties of non-starch polysaccharides

A

cellulose/dietary fibre, gums, pectin

31
Q

explain cellulose as a property of non starch polysaccharides

A

cellulose is insoluble in water. it cant be digested by the body, but it absorbs water as it passes through the intestinal tract and helps stimulate peristalsis

32
Q

explain gums as a property of non starch polysaccharides

A

gums are soluble in water. they can absorb large amounts of water to form a thick gel with a firm texture

33
Q

explain pectin as a property of non starch polysaccharides

A

present in plants cells and cell walls of fruit and vegetable. its used as a setting agent, as it can absorb water to form a gel. its only present in ripe fruits, if underripe its in the form of protopectin and if its overripe it becomes pectic acid. for pectin to be absorbed it needs heat and acid, e.g. jam-making

34
Q

what are the effects of dry heat on carbohydrates

A

-maillard reaction, e.g. roast beef
-caramelisation, e.g. crème caramel
-dextrinisation, e.g. toast

35
Q

what are the effects of moist heat

A

-syrup formation, e.g. syrup in canned peaches
-gelatinisation, e.g. white sauce
-cellulose softens, e.g. potatoes
-pectin extractions, e.g. jam

36
Q

what are the biological functions of carbohydrates

A

-supply the body with heat and energy. helps keep the body at 37C
-excess carbohydrates intake is converted to glycogen and stored in the liver and muscles as a long-term energy reserve
-cellulose/dietary fibre absorbs water as it passes through the intestinal tract and helps stimulate peristalsis. this is beneficial as it speeds up the passage of food and waste, preventing bowel disorders, e.g. constipation

37
Q
A

home economics (35 decks)

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