1.1 Photosynthesis Flashcards
What are minerals or mineral salts?
They are nutrients that living organisms need in small amounts
for health, growth and repair.
What is a chemical reaction?
It is a change in which new substances are produced
What is a reactant?
It is a substance that changes in a chemical reaction
to form products
What is a product?
It is a substance that is made during a chemical reaction
What is another name for reactant?
Raw material
What is glucose?
It is a sugar made by:
a. digesting carbohydrates (in animals)
b. photosynthesis (in plants)
What is photosynthesis?
It is a series of chemical reactions in which carbon dioxide and water
are converted to glucose and oxygen
What is chloroplast?
It is the green part of a cell that contains chlorophyll
What is chlorophyll?
It is the green substance that absorbs light to get energy
for photosynthesis
What is diffusion?
The spreading out of particles from where there are many (high concentration) to where there are fewer (low concentration)
What is a guard cell?
It is a cell that helps to form stoma in a leaf, to allow gases in and out.
What is a stoma?
It is a hole in a leaf, formed between two guard cells.
What is a xylem cell?
It is a plant cell that is adapted to form hollow tubes to transport water.
What is aerobic respiration?
It is respiration that requires oxygen to release energy from glucose.
What is carbohydrate? Give two examples.
It is a nutrient needed for energy
Examples are:
1. starch
2. sugars (like glucose)
What is a compound?
It is a substance made from elements
What is an element?
It is a substance that contains only one type of atom
What is starch?
It is a large, insoluble carbohydrate made by plants to store energy.
It is an important energy source in human diets.
What is sugar?
It is soluble carbohydrate, which exists as small molecules.
Glucose is an example.
What is iodine solution?
It is a liquid that turns from orange to blue-black when added to starch.
What is hazard?
It is the harm that something may cause.
What is risk?
It is the chance of a hazard causing harm.
What does “anomalous result” mean?
It is a result that is very different from what you expect based on other results, perhaps because you made a mistake while recording it or something unexpected happened.
What does “ reliable” mean?
Measurements are reliable when repeated measurements give results that are very similar
What does “ repeatable” mean?
Results that are the same each time they are taken, when the same method and equipment are used.
Why do plants do not grow under the trampoline?
Plants require the following resources from their habitats:
Light
Warmth
Carbon dioxide gas
Water
Minerals
Because there is no light, plants do not grow under the trampoline
Why are there not many plants in sandy deserts?
Because there is very little water.
What are the raw materials for photosynthesis?
Carbon dioxide and water
What are the products of photosynthesis?
Glucose and oxygen
What makes chloroplasts green?
Chlorophyll
What is the function of chlorophyll?
It absorbs energy from light.
This energy is used to power photosynthesis.
A lot of the energy is then stored in the glucose that is produced.
What process in plants produces oxygen?
Photosynthesis
What process do humans need oxygen for?
Respiration
All organisms carry out seven life processes? For which of these do plants need carbon dioxide for?
Nutrition
Write out a summary word equation for photosynthesis ?
Carbon dioxide + Water ————-> Glucose + Oxygen
Write “light” and “chlorophyll” in small letters above and below the arrow
Why is light not a raw material for photosynthesis?
It does not change in photosynthesis to form a product.
What is the test for oxygen?
If you light a wooden splint and blow it out, it glows. If you put the glowing splint into pure oxygen, it relights.
Draw a diagram of a leaf cell and label the parts
Draw a diagram to show how to collect the gas made by pondweed.
Draw a diagram to explain how leaves are adapted for photosynthesis?
What gas from the air needs to enter leaves through stoma for photosynthesis?
Carbon dioxide
Which cells bring liquid raw material for photosynthesis into a leaf?
Xylem cells in a vein carry water into a leaf
What do we call water when it is a gas?
Water vapour
Describe how a cell gets reactants for photosynthesis?
Carbon dioxide diffuses from air through stoma into the leaf
Water is carried by xylem cells in the veins of the plant to the leaf cells
How do plants lose water from their leaves?
Xylem cells in a vein carry water into a leaf and into its cells.
Some water evaporates from cells and becomes a gas.
Water vapor diffuses out of the leaves via stoma
Since plants lose water through stomata they need a constant supply of water
Pairs of guard cells open and close the stomata between them. In some plants stomata close if it gets very hot. Explain how this helps the plant?
It helps the plant by preventing loss of water.
Carbon dioxide is a ———
compound
What process in a plant cell produces carbon dioxide?
Respiration
What elements does glucose (carbohydrate) contain?
Carbon, hydrogen, oxygen
By what process does a plant make glucose?
Photosynthesis
Why does photosynthesis stop at night?
Because there is no light.
When photosyntheis stops, the plant uses starch to make other compounds, which it transports out of the leaves.
When would you find most starch in the leaf? Why?
At the end of the day.
Plants use glucose made during photosynthesis to make starch.
Since maximum amount of glucose would have been produced at end of the day, maximum starch will be found at that time.
How do you test for starch in a leaf?
Heat the leaf in ethanol. This removes chlorophyll and removing the chlrophyll helps to show the colour of iodine better.
Add iodine ; it changes from orange to blue-black colour.
What do plants use glucose for?
Aerobic respiration
To make compounds, sometimes with the help of minerals
Draw a diagram to show how to test leaves for starch?
What happens if you keep a plant in a dark place for 2 days and then test the leaves for starch?
The results for presence of starch will be negative. Iodine will not change colour from orange to blue-black.
Draw a table to show the hazards and how to control the risks with iodine and ethanol
Iodine - Stains Skin and Clothing, stings if it gets in your eyes
Wear eye protection, don’t touch and keep clothes away from it
Ethanol - flammable, don’t use near flames. Irritates eyes, Wear eye protection
When a gas burner heats things, it gets very hot.
What is hazard of using a gas burner?
Fire, causing burns
Wear gloves and eye protection to prevent burns
