Ch3: Food

Question 1

What is nutrition?

Answer 1

The way in which organisms obtain and use food

Question 2

What are nutrients?

Answer 2

the substances in food that are used by organisms

Question 3

What are nutrients necessary for?

Answer 3

-Energy
-Growth and repair
-Metabolic reactions

Question 4

How many elements mainly make food?
Of which, which are called minerals?

Answer 4

14

All except for carbon, hydrogen and oxygen are minerals

Question 5

What are the 6 most common elements in food?

Answer 5

-Phosphorus
-Hydrogen
-Oxygen
-Nitrogen
-Carbon
-Sulfur

PHONCS

Question 6

Which elements are trace elements (only required in tiny amounts)?

Answer 6

-Zinc
-Iron
-Copper

ZIC

Question 7

What elements are present as dissolved salts?

Answer 7

-Sodium
-Magnesium
-Chlorine
-Calcium
-Potassium

Salty Milk Can’t Choose Potatoes

Question 8

What are biomolecules?

Answer 8

Chemicals that are made inside a living thing

Question 9

What are the 4 major biomolecules in food?

Answer 9

-Lipids (fats/oils)
-Carbohydrates
-Vitamins
-Proteins

LCVP
link molecules (modules)

Question 10

What elements are present in carbohydrates?

Answer 10

-Carbon
-Hydrogen
-Oxygen

Question 11

What is the ratio of the elements for carbohydrates?

Answer 11

Cx(H2O)y Where x = y

Question 12

What are the 3 types of carbohydrates?

Answer 12

-Monosaccharides
-Disaccharides
-Polysaccharides

Question 13

Describe monosaccharides

Answer 13

-Single sugar unit
-Smallest type of carbohydrate
-Sweet to taste and soluble in water
-Examples: Glucose, Fructose and, Galactose

Question 14

Describe disaccharides

Answer 14

-Made of 2 sugar units joined together
-Sweet-tasting and soluble in water
-Examples: Maltose (2 glucose molecules), Sucrose (A glucose joined to a fructose)

Question 15

Describe polysaccharides

Answer 15

-Made of many sugar units
-Insoluble or slightly soluble in water
-Not sweet-tasting
-Examples: Starch, cellulose, glycogen

Question 16

Describe starch

Answer 16

-Made of many glucose molecules joined together
-The carbohydrate stored by plants
-Easily digested as only two chemical bonds must be broken to release a glucose

Question 17

Describe cellulose

Answer 17

-Made of many glucose molecules joined together by cross-bonding
-Very strong
-Very difficult to digest

Question 18

Describe glycogen

Answer 18

-Made of large numbers of glucose molecules arranged in branched chains
-Animals store glycogen in their liver and muscles

Question 19

Name 4 sources of carbohydrates

Answer 19

-Bread
-Pasta
-Rice
-Sugars
-Fruits
-Sweets
-Cakes

Question 20

What is the structural role of carbohydrates?

Answer 20

Cellulose is used to form plant cell walls

Question 21

What is the metabolic role of carbohydrates?

Answer 21

-Glucose is broken down in respiration to release energy
-Glucose is made in photosynthesis

Question 22

What are the elements in lipids?

Answer 22

Contain carbon, hydrogen and oxygen (very little oxygen)

Question 23

What is the structure of lipids?

Answer 23

The smallest lipids have 1 molecule of glycerol linked to 3 fatty acid molecules (triglycerides)

Question 24

What are phospholipids?

Answer 24

Fat-like substances in which one of the fatty acids is replaced by a phosphate group or has a phosphate group added to it

Question 25

What are sources of lipids?

Answer 25

-Butter -Margarine -Fat on meat -Fried food -Cream -Avocado -Oil

Question 26

What are the structural roles of lipids?

Answer 26

-They are an important place to store energy in plants and animals (twice as much as carbohydrates) -They provide heat insulation and protect organs -Lipids combine with phosphorus (phospholipids) and with proteins (lipoproteins) to form cell membranes

Question 27

What is the metabolic role of lipids?

Answer 27

They can be broken down in respiration to release energy

Question 28

What are the elements in proteins?

Answer 28

Carbon Hydrogen Oxygen Nitrogen (sometimes small amounts of sulfur, phosphorus and other elements)

Question 29

Describe the structure of proteins

Answer 29

-Composed of amino acids -Amino acids are joined by a peptide bond

Question 30

1. How many amino acids exist? 2. What is a peptide? 3. What is a polypeptide?

Answer 30

1. 20 2. A peptide has less than 20 amino acids 3. A polypeptide has more than 20 amino acids

Question 31

1. What does protein folding do? 2. What does incorrect protein folding do?

Answer 31

1. Protein folding determines how a protein will work 2. Incorrect protein folding produces prions which cause diseases like BSE in cattle and CJD in humans

Question 32

What is fibrous protein? Give examples

Answer 32

Fibrous protein has little or no folding and are strong and tough e.g. Keratin in hair, nails, and feathers

Question 33

What is globular protein? Give examples

Answer 33

Globular proteins have lots of folding and form rounded shapes e.g. Egg whites (albumin) and enzymes

Question 34

What are sources of proteins?

Answer 34

-Meat -Fish -Eggs -Nuts -Milk -Peas -Beans

Question 35

What happens to excess amino acids?

Answer 35

Because amino acids are not stored in the body, excess amino acids are converted into urea in the liver in a process called deamination. The urea is carried in the blood to the kidneys and excreted in urine

Question 36

What is the structural role of proteins?

Answer 36

-Fibrous protein found in skin and hair (Keratin) -Myosin found in muscle

Question 37

What is the metabolic role of proteins?

Answer 37

-Used as enzymes to control reactions -Form antibodies to fight infections -Hormones regulate body reactions

Question 38

Name a water-soluble vitamin and a fat-soluble vitamin

Answer 38

Water-soluble: Vitamin C Fat-soluble: Vitamin D

Question 39

What are sources of vitamin C?

Answer 39

-Vegetables (peppers) -Fresh fruit (oranges)

Question 40

What is the metabolic roles of vitamin C?

Answer 40

-Forms connective tissue, bones and teeth -Involved in wound healing and the immune system

Question 41

What happens when you are deficient in vitamin C?

Answer 41

Causes scurvy -Bleeding gums, loose teeth, poor skin healing, bleeding under skin

Question 42

What are sources of vitamin D?

Answer 42

-When UV Light shines on skin -Egg yolk -Liver -Fish oils -Milk

Question 43

What is the metabolic role of vitamin D?

Answer 43

-It helps to absorb calcium from intestine -Needed for healthy bones and teeth

Question 44

What happens when you are deficient in vitamin D?

Answer 44

Causes rickets (osteomalacia in adults) -Weak, deformed bones that break easily

Question 45

Name 2 minerals plants need and their function

Answer 45

-Magnesium: needed to form chlorophyll -Calcium: holds cell walls together

Question 46

Name 2 minerals animals need and their function

Answer 46

-Iron: helps form haemoglobin -Calcium: helps form bones and teeth

Question 47

Why is water important for living things?

Answer 47

-Universal solvent- most things dissolve in it -Transports materials -Participates in chemical reactions -Moves in and out of cells to give them the correct shape -Good absorber of heat, which provides a stable temperature for living things and their reactions -Component of cytoplasm, tissue fluid and blood plasma

Question 48

What percentage of cell mass is water?

Answer 48

75%-90%

Question 49

What is metabolism?

Answer 49

The sum of all the chemical reactions in an organism

Question 50

What are anabolic reactions?

Answer 50

They use energy to convert smaller molecules to larger molecules e.g. formation of muscle from amino acids, photosynthesis

Question 51

What are catabolic reactions?

Answer 51

They release energy when a large molecule is broken down to smaller ones e.g. Digestion, respiration

Question 52

How do you test for reducing sugar?

Answer 52

-Control: water + Benedict's solution -Test: Diluted honey + Benedict's solution -Hot water bath -If reducing sugar is present- blue to turn brick red

Question 53

How do you test for starch?

Answer 53

-Control: Water + Iodine -Test: Starch solution + iodine -If starch is present the mixture will turn yellow to blue-black

Question 54

How do you test for fat?

Answer 54

-Brown pieces of paper -Control: 2 drops of water -Test: 2 drops of oil -Wait to dry -If fat is present, there will be a permanent translucent stain when held up to a light source

Question 55

How do you test for protein?

Answer 55

-Control: water + Sodium hydroxide and copper sulfate solution -Test: Milk + Sodium hydroxide and copper sulfate solution -If protein is present, it will be purple