Unit 5 Lesson 2: Photosynthesis Flashcards
Your body needs energy to function, but have you ever thought about where that energy comes from? It all begins with the
sun
How does the sun influence eevry human being
Plants convert energy from the sun into food and then the plants are eaten by animals. So, whether you are an herbivore, an omnivore, or a carnivore, the energy that powers your body originally came from the sun.
What is photosynthesis
rocess that transforms light energy into stored chemical energy
What does photosytnehis mean
photosynthesis is the process that transforms light energy into stored chemical energy. The term photosynthesis means taking light (photo) and creating something (synthesis) with it.
Give examlples of things that use phototsyntesis
. Plants, algae and some bacteria use light energy to make sugars. These sugars are where the chemical energy is stored until it can be used.
How to demonstrate photosynthesis
carbon dioxide + water + light energy  yields  sugars + oxygen
How to demonstrate photosynthesis using a chemical equation
6CO2 + 6H2O + light → C6H12O6 + 6O2
What are the reactants and products of photosynthis
Notice that the main input, or reactants, are light, water and carbon dioxide. The outputs, or products, are oxygen and sugars.
Leaves have several layers of cells and little pores called
stomata
Stomata have two main funcations what are they
transpiration and gas exchange.
How does Stomata use gas exchange
they facilitate gas exchange by allowing carbon dioxide to go into a leaf and oxygen molecules to exit the leaf.
How does Stomata use transpiration
They regulate water movement through transpiration.
Stomata have specialized cells called ? along their border.
guard cells
What do guard cells control
Guard cells control whether the stomata opens or closes, as well as the size of the opening. They respond to environmental triggers to determine if the stomata should be open or closed.
How can water vapor leave a plant
Water vapor can also exit the plant through the open stomata.
When do the guard cells open
If the concentration of carbon dioxide in the leaf is low, the guard cells open the stomata, letting in carbon dioxide. Usually, this happens during the daytime, when the plant is photosynthesizing.
How does the oxygen that is produced during phototsytnhies leave
The oxygen that is produced during photosynthesis exits the leaf through the open stomata.
What are the reasons why stomata stays closed a night
At night, when photosynthesis is not occurring, the stomata closes to prevent water loss.
Why does Stomata change in shape
Stomata change in shape and size often, constantly trying to maximize photosynthesis and minimize water loss in a plant.
How has the stomata in plants in hot areas adapt
Some plants, like those in hot, arid regions, have adapted to open their stomata during the night. They take in less carbon dioxide and photosynthesize at a lower level than regular plants, but they conserve water this way.
Where does photosynthesis take place (be exact)
Photosynthesis takes place inside the chloroplasts of plant cells.
What does chloroplast mean
organelle in a green plant cell that conducts photosynthesis
Inside the chloroplast are small, flat, sack-like structures called
thylakoids
What does thylakoid mean
sack-like structure surrounded by a membrane inside chloroplasts where the light-dependent reactions of photosynthesis occur
Thylakoids are stacked into towers called
grana (granum are multiple grana)
Thylakoids are stacked into towers called grana (granum are multiple grana) and are surrounded by a liquid called ?.
Stroma
What is stroma
fluid-filled space that surrounds the stacks of thylakoids inside the chloroplast, within which the light-independent reactions of photosynthesis occur
Thylakoids contain a green pigment called ?, which captures energy from the sun.
chlorophyll
What is chlorophyll
green pigment that captures the energy from the sun
Photosynthesis occurs in two stages:
a light-dependent stage and a a light-independent stage
Where does the light-dependent stage of phototsytnhis occur
a light-dependent stage that occurs in the thylakoid membrane
Where does the light-independent stage of phototsytnhis occur
a light-independent stage that occurs in the stroma.
light-dependent reactions
a series of reactions that take the light energy that is captured by the chlorophyll and convert it into chemical energy in the form of NADPH and ATP; consists of photosystem II, the electron transport chain, photosystem I and hydrogen ion movement and formation of ATP
What do Light-dependent reactions require
light-dependent reactions are processes that require light.
Where do light-dependent reactions take place
Light-dependent reactions take place in the thylakoid membrane.
What is the overall purpose of light-dependent reactions
These reactions take light energy that is captured by chlorophyll and convert it into chemical energy in the form of NADPH and ATP.
What is photosystem II
protein complex where light is absorbed, water is split, hydrogen ions are created, and oxygen is released during photosynthesis
What is the first stage of Photosystem II
In this protein complex, light energy raises some of the electrons in the chlorophyll to a higher energy level.
In the first stage of photosystem II In this protein complex, light energy raises some of the electrons in the chlorophyll to a higher energy level. What are the reacnts and products
Reactants:Sunlight excites electrons ( e−
).
Products:Excited electrons