BIO 1404 OPENSTAX CHAPTER 8-11 EXAM #3 REVIEW

CH8 - Photosynthesis

CH9 - Cell communication

CH10 - Cell reproduction

CH11 - Meiosis and sexual reproduction

CH8: PHOTOSYNTHESIS

8.1

❏ Photosynthesis is a biological process that captures sunlight and converts it to

chemical compound (carbohydrates which are stored in C-C compounds)

❏ Carbohydrates - used by organisms to power metabolism (ex. cellular respiration)

❏ Only plants, algae and cyanobacteria perform photosynthesis - called

photoautotrophs

❏ Animals, fungi and other bacteria rely on sugars made from photosynthesis -

called heterotrophs

❏ Chemoautotrophs synthesizes sugar by extracting energy from inorganic

compounds, not by capturing sunlight

❏ Photosynthesis requires carbon dioxide, water and sunlight, produces glucose

and oxygen, takes place in the organelle chloroplast (throughout the cytoplasm)

❏ Photosynthesis takes place in the middle layer of the leaf called mesophyll

❏ Gas exchange of carbon dioxide and

oxygen occurs through small,

regulated openings called stomata ,

located on underside of the leaf and

surrounded by a pair of guard cells,

also helps to minimize water loss

❏ Structure of the chloroplast

❏ Chlorophyll are embedded in the

thylakoid membrane

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❏ Chlorophyll is a small pigment that absorbs colors of light except for green, the

reason why it is green it’s because it absorbs other colors of light such as blue

and red and green is reflected out

❏ Two major stages of photosynthesis:

- Light-dependent reactions: energy from sunlight is absorbed by

chlorophyll, converted it into chemical energy

- Calvin cycle (AKA

light-independent reactions,

dark cycle): assembly of the

sugar molecules

❏ Energy carriers are used over and

over again, once they obtain full

energy in light dependent

reactions, they will move and

release energy in the Calvin cycle

and go back to obtain more energy

❏ Light-dependent reactions require

sunlight, light-independent reaction

can be performed in presence of sunlight or not

❏ Differences between light-dependent reactions and light-independent reactions

Light-dependent reactions Light-independent reactions (Calvin cycle)

Location: thylakoid membrane of chloroplast Location: stroma of the chloroplast

Light energy is absorbed by photosystem I

and II (chlorophyll involved)

CO2 in the atmosphere is absorbed

Cyclic and noncyclic phosphorylation occur

in the cells

C3 pathway in green plants and C4 in desert

plants

Products: ATP, NADPH End products are used to synthesize sugar

Oxygen is released as a byproduct Main product is sugar in the form of glucose

8.2

❏ Amount of energy is measured by wavelength, the distance between consecutive

points of a wave

❏ The electromagnetic spectrum is the range of all possible frequencies of radiation

(plants only absorb light in the wavelength range of 700 nm - 400 nm)

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