bio revision T-1

Question 1

what is an enzyme?

Answer 1

enzymes are proteins that act as biological catalysts that speed up the rate of reaction without going through any changes themselves

Question 2

explain lock and key hypothesis

Answer 2

enzyme is specific, lock is enzyme and key is substrate. The substrate will come and fit into the active site of the enzyme and form enzyme substrate complex.The substrate then turns into products and leaves the active site free for other substrates.

Question 3

define diffusion

Answer 3

movement of particles from region of high concentration to a region of lower concentration down a concentration gradient as a result of their random movement

Question 4

define osmosis

Answer 4

movement of water molecules from a region of high water potential to region of low water potential through a partially permeable membrane

Question 4

examples of diffusion in living organisms

Answer 4

• respiration
• blood molecules diffuse into the blood stream in the small intestine
• Oxygen molecules diffuse into the bloodstream in the lungs.

Question 4

what does diffusion help living organisms to do

Answer 4

• helps obtain many of their requirements
• gets rid pf many of their waste products
• carries out gas exchange for respiration

Question 5

write the word equation for photosynthesis

Answer 5

carbon dioxide+Water→Sunlight(over arrow) chlorophyll (bellow arrow) glucose + oxygen

Question 6

write the chemical equation of photo synthesis

Answer 6

6CO2 + 6H2O → C6 H12 O6 + 6O2

Question 7

how many µm is 1mm

Answer 7

1000

Question 8

differences between monocots & dicots

Answer 8

1) monocot embryos have a single cotyledon

the dicot embryos have a pair of cotyledons

2) monocots have fibrous root systems

dicots have tap root systems

3) in monocot flowers the count of parts of the flower is three or multiples of 3

the part count in dicot’s is a multiple of four or five or equal tot 4/5

Question 9

examples of a monocot

Answer 9

wheat, corn, & grass

Question 10

examples of dicots

Answer 10

beans, apple, & pear

Question 11

why do experiments have controls

Answer 11

it has all the conditions to grow so it is there to compare with the experiment

Question 12

what is the function of magnesium ion in plants

Answer 12

mg is needed to make chlorophyll

Question 13

function of nitrate ion in plants

Answer 13

nitrates are a source of nitrogen needed to make amino acids ( to build proteins)

Question 14

defficiency of mg ions causes ?

Answer 14

yellowing between the veins of the leaves (chlorosis)

Question 15

defficiency of nitrate ions causes ?

Answer 15

stunted growth and yellowing of the leaves

Question 16

what is the optimum temp where enzymes are most active

Answer 16

37 degrees celsius ( whatever closest to the human body temp)

Question 17

what ph is enzymes most effective at

Answer 17

between 6 & 8

Question 18

efficiency of mg ions causes ?

Answer 18

yellowing between the veins of leaves (chlorosis)