Y10 Photosynthesis reaction & uses of glucose from photosynthesis

What type of chemical reaction is photosynthesis?

An endothermic reaction

What is an endothermic reaction?

A chemical reaction that takes in energy from the environment overall/requires energy for it to take place; in the case of photosynthesis, energy transferred by light

What is the word equation for photosynthesis?

Carbon dioxide + water -> glucose + oxygen, with light (and chlorophyll) above (and below) the arrow

What is the balanced symbol equation for photosynthesis?

6CO2 + 6H2O -> C6H12O6 + 6O2 (all numbers following an element are subscript)

What is chlorophyll, where is it found and what is its function?

A green pigment found in chloroplasts that absorbs energy transferred by light for photosynthesis

From where does a plant obtain carbon dioxide? Where and how does it enter the plant?

From the atmosphere/air; it diffuses through the stomata (holes) into the leaves

From where does a plant obtain water? Where and how does it enter the plant?

From the soil; it diffuses by osmosis into the root hair cells

How are photosynthesis and respiration related?

Photosynthesis makes glucose, which is then used in respiration

Why do plants need to carry out respiration?

To release energy to carry out chemical reactions (e.g. protein synthesis)

Recap from year 9: which solution tests for the presence of glucose? What do you have to do to it? What is a positive result in this test?

Benedict's solution; heat in a water bath; turns from blue to green/yellow/orange/brick red

Which 2 types of molecules can the glucose produced in photosynthesis be converted into in order to store energy?

Starch or lipids (fats or oils)

Recap from year 9: which solution tests for the presence of starch? What is a positive result in this test?

Iodine solution; turns from yellow/orange-brown to blue-black

Recap from year 9: what is used to test for the presence of lipid? What is a positive result in this test?

Ethanol and water; turns from colourless to a cloudy white emulsion

What can the glucose produced in photosynthesis be converted into in order to strengthen cell walls?

Cellulose

With which mineral ions can glucose be combined to produce amino acids?

Nitrate ions

Recap from year 9: what are amino acids needed for?

Protein synthesis/to make proteins (which takes place at the ribosomes)

Recap from year 9: which solution tests for the presence of protein, and what is a positive result in this test?

Biuret solution; turns from blue to purple

With which mineral ions can glucose be combined to produce chlorophyll?

Magnesium ions

Recap from year 9: from where, and how do mineral ions enter a plant?

From the soil; absorbed by root hair cells by active transport