photosynthesis

Question 1

what is photosynthesis

Answer 1

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms’ activities (energy transformation).

Question 2

write brief notes on photosynthesis

Answer 2

Photosynthesis is essential to all life on earth; both plants and animals depend on it. It is the only biological process that can capture energy that originates in outer space (sunlight) and convert it into chemical compounds (carbohydrates) that every organism uses to power its metabolism.

Question 3

how is sunlight energy used in photosynthesis

Answer 3

In brief, the energy of sunlight is captured and used to energize electrons, which are then stored in the covalent bonds of sugar molecules.

Question 4

give examples of organisms that perform photosynthesis

Answer 4

Plants,
algae,
and a group of bacteriacalled cyanobacteria

Question 5

what are chemotrophs

Answer 5

these are group of bacteria that synthesize sugars, not by using sunlight’s energy, but by extracting energy from inorganic chemical compounds

Question 6

what is the importance of photosynthesis

Answer 6

it helps to store the energy in solar radiation (the “photo-” part) as high-energy electrons in the carbon-carbon bonds of carbohydrate molecules (the “-synthesis” part)

Question 7

summarise briefly the process of photosynthesis

Answer 7

Photosynthesis is a multi-step process that requires sunlight, carbon dioxide (which is low in energy), and water as substrates

After the process is complete, it releases oxygen and produces glyceraldehyde-3-phosphate (GA3P), simple carbohydrate molecules (which are high in energy) that can subsequently be converted into glucose, sucrose, or any of dozens of other sugar molecules.
These sugar molecules contain energy and the energized carbon that all living things need to survive.

Question 8

what are the products involved in photosynthesis

Answer 8

Photosynthesis uses solar energy, carbon dioxide, and water to produce energy-storing carbohydrates.
Oxygen is generated as a waste product of photosynthesis.

Question 9

name the compound from which glucose is made during photosynthesis

Answer 9

Glucose, the primary energy source in cells, is made from two three-carbon GA3Ps.

Question 10

which structure of the leaf does photosynthesis occur

Answer 10

photosynthesis generally takes place in leaves, which consist of several layers of cells. The process of photosynthesis occurs in a middle layer called the mesophyll. The gas exchange of carbon dioxide and oxygen occurs through small, regulated openings called stomata (singular: stoma

Question 11

what is the function of the stomata(STOMA)

Answer 11

it play roles in the regulation of gas exchange and water balance.

Question 12

what is the location of the stomata in a leaf

Answer 12

The stomata are typically located on the underside of the leaf, which helps to minimize water loss.

Each stoma is flanked by guard cells that regulate the opening and closing of the stomata by swelling or shrinking in response to osmotic changes.

Question 13

where does photosynthesis take place in cells

Answer 13

photosynthesis takes place inside an organelle called a chloroplast

Question 14

define thylakoids

Answer 14

these are disc-shaped structures found within the chloroplast

Question 15

what is found embeded in the thylakoids

Answer 15

chlorophyl which is pigment (molecule that absorbs light) responsible for the initial interaction between light and plant material, and numerous proteins that make up the electron transport chain is found in the Thylakoids

Question 16

what is a granum

Answer 16

it is a group or a stack of thylakoids

The thylakoid membrane encloses an internal space called the thylakoid lumen

Question 17

define the stroma(bed)

Answer 17

this is the the liquid-filled space surrounding the granum

Photosynthesis takes place in chloroplasts, which have an outer membrane and an inner membrane. Stacks of thylakoids called grana form a third membrane layer.

Question 18

whatare the stages involved in photosynthesis

Answer 18

1. the light-dependent reactions
2. the light independent-reactions

Question 19

what happens in the light dependent reaction

Answer 19

In the light-dependent reactions, energy from sunlight is absorbed by chlorophyll and that energy is converted into stored chemical energy.

Question 20

what happens in the light in-dependent reaction

Answer 20

In the light-independent reactions, the chemical energy harvested during the light-dependent reactions drive the assembly of sugar molecules from carbon dioxide.

although the light-independent reactions do not use light as a reactant, they require the products of the light-dependent reactions to function

Question 21

what does the sunlight do in the light independent reaction

Answer 21

it helps to activate several enzymes used in the light-independent reactions

Question 22

what does the light dependent reaction use to store energy

Answer 22

The light-dependent reactions utilize certain molecules referred to as energy carriers to temporarily store the energy

Question 23

what does the energy carriers do

Answer 23

they move energy from light-dependent reactions to light-independent

these energy carriers are rich in energy and after the energy is released, the “empty” energy carriers return to the light-dependent reaction to obtain more energy.

Question 24

where does the light dependent reaction take place

Answer 24

ight-dependent reactions, which take place in the thylakoid membrane, use light energy to make ATP and NADPH.

Question 25

where does the light-independent reaction takes place

Answer 25

The Calvin cycle or light-independent reaction takes place in the stroma, uses energy derived from these compounds to make GA3P from CO2.

Question 26

what is the overall function of the light dependent reaction

Answer 26

the function of light-dependent reactions is to convert solar energy into chemical energy in the form of NADPH and ATP. This chemical energy supports the light-independent reactions and fuels the assembly of sugar molecules.

Protein complexes and pigment molecules work together to produce NADPH and ATP.

Question 27

what is a photoystem

Answer 27

A photosystem consists of a light-harvesting complex and a reaction center.

Question 28

what happens in photosystem

Answer 28

Pigments in the light-harvesting complex pass light energy to two special chlorophyll a molecules in the reaction center. The light excites an electron from the chlorophyll a pair, which passes to the primary electron acceptor.
The excited electron must then be replaced.

Question 29

summary on phosynthesis

Answer 29

6CO2 + 6H2O + Light Energy → C6H12O6 + 6O2
Autotrophs store chemical energy in carbohydrate food molecules they build themselves. Most autotrophs make their “food” through photosynthesis using the energy of the sun.
Photosynthesis occurs in the chloroplast, an organelle specific to plant cells.
The light reactions of photosynthesis occur in the thylakoid membranes of the chloroplast.
Electron carrier molecules are arranged in electron transport chains that produce ATP and NADPH, which temporarily store chemical energy.
The light reactions capture energy from sunlight, which they change to chemical energy that is stored in molecules of NADPH and ATP.
The light reactions also release oxygen gas as a waste product.
The reactions of the Calvin cycle add carbon (from carbon dioxide in the atmosphere) to a simple five-carbon molecule called RuBP.
The Calvin cycle reactions use chemical energy from NADPH and ATP that were produced in the light reactions.
The final product of the Calvin cycle is glucose.