Biology 2.1 Photosynthesis Flashcards
What is photosynthesis
(Hint: where it takes place, reactants, word equation)
Photosynthesis is the process by which plants use sunlight energy and the reactants carbon dioxide and water to produce glucose and oxygen and make their own food. This process takes place in the cells of a leaf, in an organelle called chloroplast which contains chlorophyll which traps the sunlight energy that is needed for this reaction. The process of photosynthesis can be shown as a word equation
Carbon dioxide + water→ (sunlight energy, chlyll)→ glucose + oxygen
What is the importance of leaves in photosynthesis
The leaves are the main organs for photosynthesis as they obtain carbon dioxide
What is the special structure in leaves? Why do they have this structure? (how does it help them)
- They have a flat surface to trap the maximum amount of sunlight energy and are thin so that gases (such as carbon dioxide and oxygen) can easily move in and out of the leaf.
- Leaves also grow in a way so that they can get as much sunlight as possible
(These special features help them to carry out photosynthesis)
What are the tubes found in a vein of a plant? What are their functions?
One of them carries water from the soil to all the cells of the leaf. This tube is the Xylem Vessel. The other tube carries food from the leaves to the rest of the plant body. The name of the tube is the Phloem Vessel. These two tubes make up the Mid Vein,
Diagram of the internal structure of a leaf
What are the apparatus needed for the experiment of extracting chlorphyll
To extract chlorophyll from the cells of a green leaf, we must have: a beaker, bunsen burner, a tripod, boiling tube, reagent chemical (ethanol), and water.
What are the steps in the experiment of extracting chlorophyll
Firstly we must boil some water in a beaker by placing it on a bunsen burner with a tripod.
Then, we place a piece of a leaf into the boiling water to soften it.
We must next pour some ethanol into a boiling tube (78*C).
We must take the leaf out of the boiling water and put it into the boiling tube with ethanol.
Then we must reheat the ethanol (by placing
What is the result of this experiment?
We observe that the boiling tube of ethanol has changed color from colorless to green. (This is because it now contains the chlorophyll or green pigment which had been extracted from the leaf)
Some white patches had appeared on the leaf (because the chemical which gave the leaf color had been extracted from it).
State the advantage of the spongy mesophyll cells’ round and irregular shape
Due to the their round shape, some air spaces/gaps may appear between them.
What is the function of the stomata
Stomata are tiny opening pores on the lower epidermis of a leaf. It allows gases like oxygen and carbon dioxide to move in and out of the leaf.
What is the function of the waxy cuticle
The waxy cuticle, a transparent, waxy substance that lays on the upper and lower epidermis, protects that part of the leaf. The waxy cle also controls the loss of water of the leaf by transpiration.
What is the function of the guard cells
Guard cells make up the stomata, provide protection and have gaps in between them which allow the movement of gases.
What food do plants produce and how do they use it
Plants make glucose, which is a carbohydrate and use it to obtain energy for respiration, growth and repair. It is also used as a raw material to make proteins (by using nitrate from the soil). The extra glucose/leftovers are changed into starch to be stored in their body.
