Photosynthesis Flashcards
What are autotrophs?
Organisms that make food on their own
What are heterotrophs?
Organisms that obtain energy from food
What is an examnple of an autotroph?
A plant
What is an example of a heterotroph?
A human
How is ATP different from ADP?
ADP only has two phosphate groups
When a cell has energy available, how can it store small amounts of energy?
By adding a phosphate group to ADP, producing ATP
When is the energy stored in ATP released?
By breaking the bond between the second and third phosphate
Why is ATP so useful for cells?
The energy it stores
What are two ways in which cells use energy provided by ATP?
Protein Synthesis
Muscle Contractions
Why is it useful for cells to keep a small amount of ATP on hand?
It is not good for large amounts of energy. A sugar molecule stores 90x that of 1 ATP
Where do cells get the energy to regenerate ATP?
Foods like glucose
What occurs during photosynthesis?
Plants convert sunlight energy from H2O and CO2 to carbohydrates
Who discovered that most of a plants mass is water?
Jan van Helmont
What did Jan Ingenhousz show?
Plants produce oxygen when they are in light
What is the formula for photosynthesis?
CO2 + H20 + Light → Sugar + Oxygen
Photosynthesis uses the energy of sunlight to convert what things?
Water and carbon dioxide into oxygen and high energy carbohydrates
What does photosynthesis require in addition to water and CO2?
Light and chlorophyll
What light absorbing molecules gather the suns energy?
Pigments
What is the principal pigment of plants?
Chlorophyll
What regions of the visible light spectrum does chlorophyll absorb well?
Blue-violet region
Red region
What sac like membranes do chloroplast contain?
Thylakoids
What is a granum?
Stacks of thylakoids
What is a stroma?
The region outside the thylakoid membranes
What are the two stages of photosynthesis called?
Light independent reactions
Light dependent reactions
When sunlight excites electrons in the chlorophyll, how do the electrons change?
They gain much energy
What is a carrier molecule?
Compounds which take in a pair of high energy electrons and transfer them to another molecule
What is the carrier molecule involved with photosynthesis?
NADP+
How does NADP+ become NADPH?
NADP+ is converted to NADPH by accepting and holding two high energy electrons (e-) and one hydrogen ion (H+).
What are true things about light dependent reactions
They convert ADP into ATP
They produce oxygen gas
They convert NADP+ into NADPH
Where do light-dependet reactions take place?
In the thylacoid membrane
What dies the Calvin cycle use to produce high-energy sugars?
Uses ATP and NADPH to make sugars
Why are the reactions of the calvin cycle also called light independent reactions?
It does not require light to work
What are true things about the Calvin cycle?
Carbon dioxide molecules enter the Calvin cycle from the atmosphere
Energy from ATP and high-energy electrons from NADPH are used to convert 3-carbon molecules into higher energy forms
The Calvin cycle used six molecules of carbon dioxide to produce a single 6-carbon sugar molecule
What are three factors that affect the rate at which photosynthesis occurs?
Light intensity
Availability of water
Temperature
True or false? ATP is not good for storing large amounts of energy over time
True
Can heterotrophs obtain food from eating plant-eating animals?
Of course!
