Chapter 8 Bio
Organisms that cannot make their own food and must obtain energy from the foods they eat are called
heterotrophs
Photosynthesis uses sunlight to convert water and carbon dioxide into oxygen and glucose
high energy sugars/carbohydrates
The stroma is the space that surrounds
thylakoids
______are photosynthetic membranes inside chloroplasts
thylakoids
Jan van Helmont concluded that plants gain most of their mass from
water
The electrons that chlorophyll loses to the electron transport chain are replenished by the ______ molecule.
water
Thylakoids are arranged in stacks known as
grana
What is inside the thylakoid membrane?
Chlorophyll and other light absorbing pigments, photosystems I and II, ATP synthase, electron transport chain
Cells keep only a small amount of _______on hand and regenerate it as needed by using carbohydrates.
ATP
A membrane protein called _______ allows Hydrogen ions to pass through the thylakoid membrane.
ATP synthase
What are the three parts of an ATP molecule?
Adenine, ribose, 3phosphate groups
List three factors that affect the rate of photosynthesis
Amount of water, light intensity, temperature
What affects the rate of photosynthesis?
Amount of water, temperature, light intensity
Suppose Priestley repeated his experiment using many kinds of plants besides mint, and that when different plants were placed under the jar, the candle remained lighted for different periods of time. What would be a logical conclusion from these experiments?
Different plants release different amounts of oxygen
If you separate the pigments found in a typical plant cell's chloroplasts, what colors will you find?
Green, orange, red pigments
Why does the inside of the thylakoid membrane become positively changed during the light-dependent reactions?
H+ ions are released as water splits; H+ ions are pumped across using energy from the electron transport chain.
What is produced by the Calvin cycle?
High energy carbohydrates like glucose from 2 PGAL's, ADP+P; NADP+
What are the products of the Calvin cycle?
High energy carbohydrates: PGAL, glucose, starch
Where are photosystems I and II found?
In the thylakoid membranes
Where do the light-dependent reactions take place?
In the thylakoid membranes
Where in the chloroplast is chlorophyll found?
In the thylakoid membranes
What are the products of the light-dependent reactions?
Oxygen gas, ATP, NADPH
Which scientists showed that plants need light to grow?
Priestley and Ingenhousz
If carbon dioxide is removed from a plant's environment, what would you expect to happen to the plant's production of high-energy sugars?
Production will drop and eventually stop
If you continue to increase the intensity of light that a plant receives, what happens?
Rate of photosynthesis increases then levels off at its maximum
Be able to label
Two pictures on the review
Energy is released from ATP when
a phosphate group is removed from ATP making ADP
Identify examples of heterotrophs
animals, fungi, protozoans, most bacteria
Organisms such as plants, that make their own food are called
autotrophs
Photosynthesis required light, water, carbon dioxide, and
chlorophyll
A granum
is a stack of thylakoids
The Calvin cycle takes place in the
stroma
Ingenhousz showed that plants produce oxygen bubbles when exposed to
light
The Calvin cycle is another name for
light-independent reactions; dark reactions
A student is collecting the gas given off from a plant in bright sunlight at a temperature of 27 degrees C. The gas being collected is probably
oxygen
Plants gather the sun's energy with light-absorbing molecules called
pigments
Identify examples of autotrophs
plants, algae, cyanobacteria
Most plants appear green because chlorophyll
reflects green light; does not absorb green light
Define the terms autotrophs and heterotrophs in terms of how they obtain energy. Do heterotrophs depend on autotrophs for their survival? Explain your answer.
Autotrophs are organisms that are able to use a source of energy such as sunlight, to produce their own food. Heterotrophs cannot produce their own food and must rely on the foods they ingest for energy. Heterotrophs must either eat autotrophs directly or eat other heterotrophs that have already eaten autotrophs. Heterotrophs depend on autotrophs to harvest energy from the sun. This energy is then passed on to heterotrophs in the form of food. Without autotrophs, the sun's energy would not be available to heterotrophs and heterotrophs would eventually die out (if they could not find a new way of harvesting energy).
What chemical is converted to sugar?
Carbon dioxide
Plants take in the sun's energy by absorbing
sunlight
Describe the relationship between the light-dependent and the light- independent reactions.
The light-dependent reactions use energy from the sun to produce ATP and NADPH. The light-independent reactions (Calvin cycle) use ATP and NADPH, from the light-dependent reactions, to produce high-energy carbohydrates like PGAL, glucose and starch (and give NADP+ and ADP back to light dependent reactions).
A student exposed two plants to only red light and two plants to only green light. Which plants should grow better? Why?
The plants exposed to red light should grow better because chlorophyll absorbs red light well. IT does not absorb light in the green region well.
Identify three factors that affect the rate of photosynthesis and explain the effect of each
Three of the factors that affect the rate of photosynthesis are light intensity, temperature, and amount of water. (1) The rate of photosynthesis increases with light intensity up to a certain point, then levels off at its maximum rate. (2) Photosynthesis slows at extreme temperatures and usually has an optimal temperature for each kind of plant. Temperatures between O and 35 degree C are usually optimal for the enzymes that catalyze photosynthetic reactions. Temperatures outside this range will cause changes in the protein conformation, which will make them nonfunctional, denatured. (3) Lack of water slows down, and may stop photosynthesis.
