Semester 1 bio exam (2/2) Flashcards
What is produced as a byproduct when electrons are taken from water during the light-dependent reactions?
Oxygen gas
During the Calvin cycle, how many carbon dioxide molecules are needed to produce one sugar molecule?
Six
What happens to the majority of 3-carbon molecules produced in the Calvin cycle?
They are converted back to 5-carbon molecules
At what temperature range do photosynthetic enzymes function optimally?
0°C to 35°C
What adaptation do CAM plants use to conserve water?
They only open their stomata at night
What distinguishes C4 plants from other plants?
They form a 4-carbon compound first
What happens to the energy level of electrons after passing through the first electron transport chain?
It decreases
What is the primary role of accessory pigments in photosynthesis?
To surround and support photosystems
Which process directly uses the products of light-dependent reactions?
Calvin cycle
What adaptation helps plants in dry climates prevent water loss?
Waxy coating
In CAM plants, what happens to carbon dioxide during daylight hours?
It’s released from organic acids
What is the primary function of ATP in living cells?
To provide immediate energy for cellular work
How many phosphate groups are present in ATP?
Three
What happens when cells need to release energy from ATP?
They break bonds between phosphate groups
Compared to glucose, how much energy does ATP store?
1/90th the energy
What are organisms called that must obtain energy by consuming other organisms?
Heterotrophs
Where does photosynthesis occur in plant cells?
Chloroplasts
What is the name of the stacked membrane structures in chloroplasts?
Grana
Why do plants appear green?
They absorb all colors except green
What compound accepts high-energy electrons during photosynthesis?
NADP+
Which part of the chloroplast contains the fluid outside the thylakoids?
Stroma
What are the products of photosynthesis?
Glucose and oxygen
Which type of reactions in photosynthesis require direct sunlight?
Light-dependent reactions
What happens to chlorophyll in autumn?
It breaks down first
