(a) State four characteristics of enzymes
(b) (i) List two digestive enzymes produced in the duodenum of humans
(ii) Name the substrate that each enzyme listed in 2(b)(i) acts on.
(iii) State the products of each enzyme activity in 2(b)(ii)
(c) (i) State one way in which chlorophyll is important in plants
(ii) Name two macroelements that are required for the formation of chlorophyll in plants.
(iii) State one deficiency symptom of each macroelement named in 2 (c) (ii) above
(d) Outline the proce-dure used for testing for starch in a leaf
(b) (i) List two digestive enzymes produced in the duodenum of humans
(ii) Name the substrate that each enzyme listed in 2(b)(i) acts on.
(iii) State the products of each enzyme activity in 2(b)(ii)
(c) (i) State one way in which chlorophyll is important in plants
(ii) Name two macroelements that are required for the formation of chlorophyll in plants.
(iii) State one deficiency symptom of each macroelement named in 2 (c) (ii) above
(d) Outline the proce-dure used for testing for starch in a leaf
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Correct Answer: Option n
Explanation:
(a). Characteristic of Enzymes;
They are biological catalystsialter/speed up the rate of biological reactions
remain chemically unchanged at the end of a reaction
their actions are reversible
they are specific in action/act on specific substrates
enzymes are required in small amount
are protein in nature
they act best at optimum temperature/high temperature/denatures them/ low temperature inactivates them
specific/sensitive to pH
actions retarded by poisons/inhibitors
some required co-enzymes to function.
(b)i. Digestive enzymes produced in the duodenum of humans
Amylase
Trypsin/chymotrypsin
Lipase
ii. Substrates for each enzyme
Amylase = starch
Trypsin/chymotrypsin =protein
Lipase = fats and oil
iii. Product of enzyme activity
Amylase = maltose
Trypsin/chymotrypsin = peptones/polypeptides/peptide
Lipase =glycerol and fatty acid
(c)i. Importance of chlorophyll in plants
Absorbs/traps sunlight; for photosynthesis
ii. Macro-elements required for the formation of chlorophyll
Nitrogen
Magnesium
Iron
iii. Deficiency symptoms of each macro-element in (c)ii Nitrogen
Chlorosis/yellowing of leaves
Stunted growth
Poor flower/fruit development
MagnesiuM
Poor growth
Chlorosis/yellowing of leaves
Iron
Poor/stunted growth
Chlorosis/yellowing of leaves
(d) Procedure for test for starch
Detach/pluck off/take leaf to be tested from plant after 4 to 6 hours of exposure to sun to enable it to form starch
Put leaf in boiling water for about 30 seconds to kill the cells
Put boiled leaf in 70% warm alcohol/ethylated spirit in water bath to decolorise the leaf Rinse decolorised/brittle leaf in running cold water to soften the leaf tissues/remove alcohol
Spread out on white tiles/watch glass and add a few drops of iodine solution
Allow to stand for a few minutes
It turns blue-balck showing/indicating presence of starch.
(a). Characteristic of Enzymes;
They are biological catalystsialter/speed up the rate of biological reactions
remain chemically unchanged at the end of a reaction
their actions are reversible
they are specific in action/act on specific substrates
enzymes are required in small amount
are protein in nature
they act best at optimum temperature/high temperature/denatures them/ low temperature inactivates them
specific/sensitive to pH
actions retarded by poisons/inhibitors
some required co-enzymes to function.
(b)i. Digestive enzymes produced in the duodenum of humans
Amylase
Trypsin/chymotrypsin
Lipase
ii. Substrates for each enzyme
Amylase = starch
Trypsin/chymotrypsin =protein
Lipase = fats and oil
iii. Product of enzyme activity
Amylase = maltose
Trypsin/chymotrypsin = peptones/polypeptides/peptide
Lipase =glycerol and fatty acid
(c)i. Importance of chlorophyll in plants
Absorbs/traps sunlight; for photosynthesis
ii. Macro-elements required for the formation of chlorophyll
Nitrogen
Magnesium
Iron
iii. Deficiency symptoms of each macro-element in (c)ii Nitrogen
Chlorosis/yellowing of leaves
Stunted growth
Poor flower/fruit development
MagnesiuM
Poor growth
Chlorosis/yellowing of leaves
Iron
Poor/stunted growth
Chlorosis/yellowing of leaves
(d) Procedure for test for starch
Detach/pluck off/take leaf to be tested from plant after 4 to 6 hours of exposure to sun to enable it to form starch
Put leaf in boiling water for about 30 seconds to kill the cells
Put boiled leaf in 70% warm alcohol/ethylated spirit in water bath to decolorise the leaf Rinse decolorised/brittle leaf in running cold water to soften the leaf tissues/remove alcohol
Spread out on white tiles/watch glass and add a few drops of iodine solution
Allow to stand for a few minutes
It turns blue-balck showing/indicating presence of starch.