Chapter 8 Flashcards
Where does the energy of food originally come from?
The sun
What organisms can make their own food
Autotrophs
What kind of organisms obtain energy from food they eat?
Heterotrophs
What is one of the principal chemical compounds that living things use to store energy?
ATP (Adenosine Triphosphate)
How is ATP and ADP different?
ATP has three phosphate groups
ADP has two phosphate groups
What are two ways in which cells use the energy provided by ATP?
Active transport
Movement in the cell
(((Synthesis of proteins)))
Where do cells get their energy to regenerate ATP?
Carbohydrates
Plants gather the suns energy with sun absorbing molecules called what?
Pigments
What is the principle pigment of plants?
Chlorophyll
Why light does chlorophyll absorb light very well
Blue and red region
Chloroplast contain sacklike photosynthetic membranes called what?
Thylakoids
What is a granum
Sack of thylakoids
The region outside the thylakoid membranes in the chloroplast is called what?
Stroma
What are the two stages of photosynthesis called?
Light dependent reaction
Light independent reaction (Calvin Cycle)
When sunlight excites electrons in chlorophyll, how do the electrons change?
Electrons gain a lot of energy
What is a carrier molecule involved in photosynthesis?
NADP+
How does NADP+ become NADPH?
When it accepts a pair of high energy electrons
What reaction turned ADP into ATP?
Light dependent reaction
Why are the reactions of the Calvin cycle also called the light independent reactions?
It doesn’t require light
What three factors affect the rate at which photosynthesis occurs?
(Amount of) water (available)
Temperature
Light (intensity)
What is the process called by which plants use the suns energy to make high energy sugars?
Photosynthesis
What is the stage of photosynthesis called in which plants use the energy that ATP and NADPH contain to build high energy sugars?
The Calvin cycle
What are the reactions of the first stage of photosynthesis called?
Light dependent reactions
What is the region called that obtains energy from the food it consumes?
Stroma
What are the three parts of the ATP molecule?
Adenine, Ribose, and 3 phosphate groups
when a cell has energy available, how can it store small amounts of the energy?
By adding a phosphate group to ADP, which produces ATP
When is the energy stored in the ATP molecule released?
When ATP breaks the bond between its 2nd and 3rd phosphate groups
Why is ATP useful to all cell types?
ATP can easily store and release energy
What occurs in the process in photosynthesis?
Photosynthesis uses the energy of sunlight to convert water and carbon dioxide (reactants) into oxygen and high energy sugars (products)
Why can ATP easily release and store energy?
It does it by breaking and re-forming the bonds between its phosphate groups
How do photosynthetic organisms capture energy from sunlight?
It uses pigments
Equation for photosynthesis, words and chemical symbols
carbon dioxide + water – yields–> sugar +oxygen
6CO2 + 6H2O –((light))–> C6 H12 O6 + 6O2
What does photosynthesis require?
water, carbon dioxide, light, and chlorophyll
What is a carrier molecule?
A compound that can except a pair of high energy electrons and transfer them and most of their energy to a another molecule
What do light - dependent reactions do?
They convert ADP to ATP, produce oxygen gas, and convert NADP+ into NADPH
Where do light- dependent take place?
Within the Thylakoid membranes of the chloroplast
What happens in light- independent reactions?
High energy electrons move through the electron transport chain from photosystem II to photosystem I
Pigments in photosystem I use energy light to reenergize electrons
The difference in charges across the thylakoid membrane provides the energy to make ATP
How does ATP synthase produce ATP?
It allows H+ ions to pass through the thylakoid membrane, which rotates ATP, binding ADP and phosphate groups.
What does the Calvin cycle use to produce high energy sugars?
ATP and NADPH from the light dependent reactions
What happens in the Calvin Cycle (light independent reactions)?
Carbon Dioxide enters from the atmosphere
Energy from ATP and high energy electrons from NADPH are used to convert 3-carbon molecules into similar 3 carbon molecules
Also uses six molecules of carbon dioxide to produce a single 6-carbon sugar molecule
What is the product of light dependent reactions?
Oxygen (O`2)
What is the product of light independent reactions (Calvin cycle)?
High energy sugars
What’s the thylakoid space called?
Lumen
What is Photosystem II?
The first step in light- dependent reactions
Light energy is absorbed and produces high energy electrons, which are passed to the electron transport chain. Water molecules are split to replace those electrons, thus releasing H+ ions and oxygen.
What is photosystem I?
Comes after Photosystem II and the electron transport chain. Electrons are reenergized and then go through a second, shorter, electron transport chain. High energy electrons are picked up by NADP+, producing NADPH.
What are the three kinds of photosynthesis/plants?
C3, C4, CAM.
What is C`3 photosynthesis/plants?
most common (about 90% of plants), live in moderate environment. (CO`2 + RuBP -> 6C -> 3C)
What is C`4 photosynthesis/plants?
Very dry environment, hot or cold. 2 cell process. CO2 turns into PEP in mesophyll. When CO2 is needed, PEP goes into bundle sheath and turns back into CO2, to be used in Calvin cycle. (called C4 because it uses 4 carbon molecules at start)
What is CAM photosynthesis/plants?
Very hot environment. 1 cell process. Opens during night, closes at day. CO2 comes in during night and some goes to make a lot of malot and the rest are used in Calvin cycle. During the day malot is turned back into CO2 and is used in Calvin cycle.
Why are C`4 and CAM plants special?
They have biochemical adaptions that minimize water loss while still allowing photosynthesis to happen
