CIE IGCSE Biology Revision Notes savemyexams.co.uk
2 ORGANISATION
6 PLANT NUTRITION
OF THE ORGANISM
YOUR NOTES
CONTENTS:
6.1 PHOTOSYNTHESIS
6.2 INVESTIGATING PHOTOSYNTHESIS
6.3 LIMITING FACTORS (EXTENDED ONLY)
6.4 INVESTIGATING GAS EXCHANGE (EXTENDED ONLY)
6.5 LEAF STRUCTURE
6.6 MINERAL REQUIREMENTS
VIEW EXAM QUESTIONS
6.1 PHOTOSYNTHESIS
Photosynthesis Theory: Basics
• Green plants make the carbohydrate glucose from the raw materials carbon dioxide and
water
• At the same time oxygen is made and released as a waste product
• The reaction requires energy which is obtained by the pigment chlorophyll trapping light
from the Sun
• So photosynthesis can be defined as the process by which plants manufacture
carbohydrates from raw materials using energy from light
• It can be summed up in the following equation:
Photosynthesis word equation
EXAM TIP
If asked for the raw materials required for photosynthesis, the answer is
carbon dioxide and water. Although required for the reaction to take place,
light energy is not a substance and therefore cannot be a raw material.
CIE IGCSE Biology Resources
© copyright Save My Exams Page 1
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
6 PLANT NUTRITION
YOUR NOTES
6.1 PHOTOSYNTHESIS cont...
How plants get the materials they need
EXTENDED ONLY
Photosynthesis Theory
• The balanced chemical equation for photosynthesis is:
Balanced chemical equation for photosynthesis
• The light energy is converted into chemical energy in the bonds that are holding the
atoms in the glucose molecules together
CIE IGCSE Biology Resources
© copyright Save My Exams Page 2
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
2 ORGANISATION
6 PLANT NUTRITION
OF THE ORGANISM
YOUR NOTES
6.1 PHOTOSYNTHESIS cont...
EXTENDED ONLY
The Products of Photosynthesis
• Plants use the glucose they make as a source of energy in respiration
• They can also convert it into starch for storage, into lipids for an energy source in seeds,
into cellulose to make cell walls or into amino acids (used to make proteins) when
combined with nitrogen and other mineral ions absorbed by roots
The fate of glucose
EXAM TIP
The photosynthesis equation is the exact reverse of the aerobic respiration equation
– so if you have learned one you also know the other one!
You will usually get more marks for providing the balanced chemical equation than
the word equation.
CIE IGCSE Biology Resources
© copyright Save My Exams Page 3
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
2 ORGANISATION
6 PLANT NUTRITION
OF THE ORGANISM
YOUR NOTES
CONTENTS:
6.1 PHOTOSYNTHESIS
6.2 INVESTIGATING PHOTOSYNTHESIS
6.3 LIMITING FACTORS (EXTENDED ONLY)
6.4 INVESTIGATING GAS EXCHANGE (EXTENDED ONLY)
6.5 LEAF STRUCTURE
6.6 MINERAL REQUIREMENTS
VIEW EXAM QUESTIONS
6.1 PHOTOSYNTHESIS
Photosynthesis Theory: Basics
• Green plants make the carbohydrate glucose from the raw materials carbon dioxide and
water
• At the same time oxygen is made and released as a waste product
• The reaction requires energy which is obtained by the pigment chlorophyll trapping light
from the Sun
• So photosynthesis can be defined as the process by which plants manufacture
carbohydrates from raw materials using energy from light
• It can be summed up in the following equation:
Photosynthesis word equation
EXAM TIP
If asked for the raw materials required for photosynthesis, the answer is
carbon dioxide and water. Although required for the reaction to take place,
light energy is not a substance and therefore cannot be a raw material.
CIE IGCSE Biology Resources
© copyright Save My Exams Page 1
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
6 PLANT NUTRITION
YOUR NOTES
6.1 PHOTOSYNTHESIS cont...
How plants get the materials they need
EXTENDED ONLY
Photosynthesis Theory
• The balanced chemical equation for photosynthesis is:
Balanced chemical equation for photosynthesis
• The light energy is converted into chemical energy in the bonds that are holding the
atoms in the glucose molecules together
CIE IGCSE Biology Resources
© copyright Save My Exams Page 2
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
2 ORGANISATION
6 PLANT NUTRITION
OF THE ORGANISM
YOUR NOTES
6.1 PHOTOSYNTHESIS cont...
EXTENDED ONLY
The Products of Photosynthesis
• Plants use the glucose they make as a source of energy in respiration
• They can also convert it into starch for storage, into lipids for an energy source in seeds,
into cellulose to make cell walls or into amino acids (used to make proteins) when
combined with nitrogen and other mineral ions absorbed by roots
The fate of glucose
EXAM TIP
The photosynthesis equation is the exact reverse of the aerobic respiration equation
– so if you have learned one you also know the other one!
You will usually get more marks for providing the balanced chemical equation than
the word equation.
CIE IGCSE Biology Resources
© copyright Save My Exams Page 3
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
