ATP

Question 1

what does ATP stand for

Answer 1

adenosine triphosphate

Question 2

what is a short explanation on how ATP is created

Answer 2

To make glucose, a plant needs to make bonds between carbon atoms and hydrogen and oxygen atoms. The energy needed to create these bonds cannot be used directly from sunlight. This is why the energy coming from sun in the form ofphotonsis first turned into ATP, the energy of which is later used to make the bonds in the glucose molecule.

Question 3

give us a quick revision on how Photosynthesis works

Answer 3

• Photosynthesis:The process by whichchlorophyll in the chloroplastsof green plantsabsorbs light, carbon dioxide from the atmosphere and water from the soil to produce carbohydrates/glucose.
• Chloroplasts:Thechlorophyll-containing plastid(a membrane-bound organelle found in the cells of plants) in the cytoplasm of a plant cell.
• Chlorophyll:Thegreen, light-trapping pigment found in chloroplasts within plant leaves.
• Thylakoids:Themembrane-bound compartmentsinside chloroplasts.
• Grana:Stacks of disks that are frequently formed by thylakoids.
• Stroma:The colourless fluid surrounding the grana within the chloroplast.

Question 4

what are the two phases in Photosynthesis

Answer 4

Two phasescan be distinguished in photosynthesis:

• The light-dependent phase(only takes place in the presence of light).
• The dark phase,also known as thelight-independent phase(can take place with or without the presence of light).

The light phase

• Occurs in thegranaof the chloroplast, where the chlorophyll in the thylakoids absorbs the light energy.
• Light is absorbed andtransformed(changed)intochemical energywhich is used for:
  1. The splitting of water molecules into energy-rich hydrogen atoms, which are transferred into the dark phase, and oxygen atoms which are released into the atmosphere as gas. This is known asphotolysis.
  2. The formation ofATPfromADPand thenback to ADP,which thenreleases energythat will be used in the dark phase.

The dark phase (also known as the Calvin cycle)

• Occurs in thestromaof the chloroplast.
• CO2(carbon dioxide)from the air comes in through thestomataand combines with the energy-rich hydrogen atoms from the light phase, using the energy that is released from ATP (formed in the light phase).
• Energy-richcarbohydrates (glucose)are formed.
• Excess glucose is converted into starch, for storage.

Question 5

why is ATP known as the energy currency of cells

Answer 5

When a cell needs energy, adenosine triphosphate (ATP)is broken down and the energy is released. Cells use this energy to produce important molecules such as carbohydrates. The energy provided by ATP is also needed to move substances across the cell membranes.

Question 6

how is ATP formed

Answer 6

• Plants capture and store the energy they derive from light, during photosynthesis in ATP molecules.
• Adenosine triphosphate(ATP) is a nucleotide consisting of anadenine baseattached to aribose sugar, which is attached tothree phosphate groups. These three phosphate groups are linked to one another by two high-energy bonds calledphosphoanhydride bonds.
• ATP is broken down intoadenosine diphosphate (ADP), and a phosphate molecule along with energy that is released when the energy-rich bond is broken; this process is calleddephosphorylation.
• Energy from chemical reactions is used to form a bond between ADP and phosphate(P) to form ATP. ATP will release this energy again later as needed.