Unit 1: The Chemistry Of Life Flashcards Preview

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Flashcards in Unit 1: The Chemistry Of Life Deck (79):
1

Types of compounds

Organic and inorganic

2

What are organic compounds?

•Compounds that don't contain carbon
•Not produced by living organism

3

Eg of inorganic compounds

Water
Gases
Mineral salts

4

What inorganic compounds contain carbon

CO2 and CO and carbonates because they don't have carbon hydrogen bonds

5

What are organic compounds?

•Chemical compounds that contain carbon
•Produced by living organisms

6

Eg of organic compounds

Carbohydrates
Lipids
Proteins
Nucleic acids
Vitamins

7

Most important inorganic compound?

Water

8

Functions of water in living organisms

•Solvent
•Medium in which chemical reactions occur
•Reagent during hydrolysis
•Transporting agent
•Lubricant
•Regulates body temperature
•Gives shape and rigidity

9

What are mineral salts?

Inorganic substances/elements that are needed and absorbed by living organisms

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How do living organisms absorb mineral salts?

Plants - absorb from soil
Animals - obtain from the food we eat

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Two groups of mineral salts

•Macro-elements-needed in large quantities
•Micro-elements-needed in small quantities

12

What are the macro elements?

•Calcium
•Phosphorus
•Sodium
•Pottasium



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What are the micro-elements?

•Iron
•Iodine

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Functions of calcium

•Build strong bones
•Blood coagulation (clotting)
•Plays role in permeability of cell membranes
•Plays a role in muscle contraction and nerve impulse transmission

15

Calcium deficiencies

Human- rickets, osteomalacia and osteoporosis

Plants - weak root growth

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Functions of phosphorus

•Builds strong bones and teeth
•Component of ATP
•Component of DNA and RNA
•Part of phospholipid in cell membranes

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Phosphorus deficiencies

Plants - stunted growth
Humans - seldom occurs

18

Sodium functions

•Maintaining water balance
•Helps with the functioning of nerves and muscle contraction
•Controls rhythm of the heart

19

Deficiencies of sodium

Humans - muscle cramps
Plants - unknown

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Potassium functions

•Maintaining water balance in the body
•Facilitates the functioning of muscles and nerves
•Helps to regulate heart rhythm
•Necessary to activate plant enzymes

21

Potassium deficiencies

Humans - seldom occurs
Plant - yellow and brown leaf margins

22

Iron functions

•Helps form haemoglobin that transports Oxygen in blood
•Helps to form chlorophyll molecules in the plants

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Deficiencies for iron

Human - anaemia
Plants - chlorosis ( yellowing of leaves)

24

Iodine functions

•For thyroxin which is secreted by thyroid gland

25

Deficiency from iodine

Goitre (swelling of the neck or larynx)

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What are the compound minerals

Phosphates(PO4)
Nitrates (NO3)

27

Functions of nitrogen

•Protein synthesis
•Nitrogen forms nucleotides of DNA and RNA and synthesis of chlorophyll

28

Explain eutrophication

•Minerals are washed away during heavy rains into rivers an dams
•Phosphates cause drastic increase in the growth of freshwater algae called algal bloom
•Algae blocks sunlight from photosynthesising organisms which results in death pf water plants
•Decomposed dead material leads to large amounts of bacteria
•Decomposition needs oxygen therefore depleting oxygen supply in water and killing fish

29

What are enzymes?

Proteins that accelerate chemical reactions inside living cells

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What are catalysts?

Substances that accelerate chemical reactions

31

What is an enzyme?

Biological catalyst that accelerates a chemical reaction by lowering the activation energy without itself being changed by the reaction

32

What are the chemical reactions that take place in living cells?

Metabolic processes

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What are the two types of metabolic reactions?

•Anabolic reactions
•Catabolic reactions

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What happens during an anabolic reaction?

A complex molecule is built up from simple molecules
•Energy is required

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What happens during a catabolic reaction?

•A complex molecule is broken down into simple molecules
•Energy is usually released

36

What is it called when water breaks down complex molecules(food) into simple molecules?

Hydrolysis

37

What is the suffix used for enzymes

-ase

38

What enzyme is used for water and maltose?

Maltase

39

What enzyme is used for water and sucrose?

Sucrase

40

What enzyme is used for water and lactase?

Lactase

41

Polysaccharide enzymes

Amylase

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Examples of carbohydrate digestive enzymes

•Maltase
•Sucrase
•Lactase
•Amylase

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Lipid digestive enzyme

Lipase

44

Protein digestive enzyme

Protease e.g pepsin

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Substrate?

Substance on which enzyme acts

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Product?

Substance formed during reaction

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What is formed when an enzyme and substrate are temporarily bonded?

Enzyme-substrate-complex

48

What happens during enzyme substrate complex stage?

•Enzyme lowers activation energy
•Substrate changes chemically and leaves active sight
•Enzyme is unchanged and ready to bond with another substrate

49

What is the lock and key model?

Action of enzymes

50

Are enzymes sensitive to temperature changes?

Yes

51

What do lower temperatures do to enzymes?

Make them temporarily inactive

52

Optimum temperature?

Temperature at which most enzymes work the best

53

What is to denature

At high temperatures the shape of the enzyme begins to change and the substrate no longer fits into the active site

54

Is denaturation reversible

No. Once it denatures, it can't return to its proper shape when the temperature is lowered.

55

What is an optimum pH?

Narrow pH range within which an enzyme can function

56

What are the properties of enzymes?

•Spherical proteins
•Sensitive to temperatures - denatures at high temperatures and becomes temporarily inactive in low temperatures
•Denature if pH changes drastically
•Substrate specific
•Enzymes can be used over and over again
•Small amount of enzyme can change a large amount of substrate

57

An enzyme in everyday life

Biological washing powders

58

What elements make up nucleic acids?

Carbon, hydrogen, oxygen, nitrogen and phosphorus

59

Two types of nucleic acids

•DNA - deoxyribonucleic acid
•RNA - ribonucleic acid

60

Where is DNA found?

Nucleus and forms part of chromatin network and chromosomes (during cell division)

61

Function of DNA

Carry hereditary characteristics and controls the structure and function of the cell

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Where is RNA found?

Nucleus and cytoplasm forms part of ribosomes

63

Function of RNA

•Protein synthesis-ensures amino acids bind to each other in a certain sequence
• According to instructions from DNA

64

What are vitamins essential for?

•Normal metabolism
•Growth
•Development of the body

65

Amount of vitamins required

Needed in small quantities and are produced by plants

66

When do vitamins need in order to perform their functions?

They must be in a solution:
•Water soluble
•Fat soluble

67

What are the water soluble vitamins

•B vitamins and vitamin C
•absorbed by the body together with water
•excess vitamins are not stored
—excreted in urine and must therefore be taken regularly

68

Fat soluble vitamins

•Vitamins A, D, E and K
•Only absorbed when dissolved in fat
•Vitamins are stored in the body

69

What do insufficient vitamins cause?

Deficiency diseases

70

Sources of vitamin A

•Yellow vegetables
•Fish
•Liver
•Egg yolk

71

Deficiency of vitamin a

Night blindness - poor vision in dim light
Xerophthalmia - dry corneas

72

Sources of vitamin B1

•Brown rice
•Wholegrain bread
•Yeast
•Legumes

73

Deficiency for vitamin B1

Beri beri - nervous disorder

74

Sources of vitamin C

•Citrus fruit
•Tomatoes
•Guavas
•Green leafy vegetables

75

Deficiencies of vitamin C

Scurvy - bleeding gums, wounds that don't heal, internal bleeding

76

Sources of vitamin D

Oily fish
Egg yolk
Liver
Milk

77

Sources of vitamin E

Leafy vegetables e.g spinach and lettuce, sunflower seeds, wholegrain and wheatgerm

78

Deficiency of vitamin D

Rickets(rachitis) - soft bones, malformed skeleton

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Deficiency of vitamin E

Rare occurrence, but neurological problems as a result of the poor transmission of nerve impulses