Chapter 8- Photosynthesis Flashcards
ATP
Adenosine Triphosphate, consists of adenine, a 5-carbon sugar called ribose, and three phosphate groups
One of the most important compounds that cells use to store and release energy
Difference between ATP and ADP
adenosine triphosphate vs adenosine diphosphate, meaning the difference is in one phosphate group. When ATP- stored energy
When ADP- already used energy
How is ATP like a battery?
ATP can easily release and store energy by breaking and re-forming the bonds between its phosphate groups, very useful as a basic energy source for all cells
Name a variety of uses for ATP?
1) provides energy for sodium potassium pumps across a cell membrane
2) used to power flagella and cilia which are motors
3) provide energy to proteins
4) used to produce light (like in the butt of fireflies)
What is a heterotroph?
Organisms that obtain food by consuming other living things
What is an autotroph?
Organisms that make their own food
Short description of phosynthesis
plants convert the energy of sunlight into chemical energy stored in the bonds of carbohydrates
What is a pigment?
light-absorbing molecules
What is chlorophyll?
the plants primary pigment. appears in two forms:
1) chlorophyll A
2) chlorophyll B
What light does chlorophyll have a hard time absorbing?
Green-thats why plants are green
What role do pigments play in the process of photosynthesis?
photosynthetic organisms capture energy from sunlight with pigments
What is a thylakoid?
interconnected sac-like photosynthetic membranes inside of a chloroplast (contain clusters of chlorophyll and proteins called photosystems)
Why does a cell only make a small amount of ATP
ATP is efficient for short term energy in quick situations like maintaining a concentration gradient (Na K pumps). Glucose is used for long term storage, having 90x the amount of energy than ATP in a stable complex
What is NADP+ ?
(nicotinamide adenine dinucleotide phosphate) Can accept and hold 2 high-energy electrons along with a hydrogen ion (H+) to make it NADPH. This is another way the energy from the sun can be converted to chemical form.
What are the reactants and products of photosynthesis?
carbon dioxide + water = (Light)= sugars + oxygen
6CO2 + 6H2O =(Light)= C6H12O6 + 6O2
What are the light-dependent reactions?
depend on photons of light. Both PS I and PS II use light captured by pigments to energize electrons.
These reactions release oxygen as a byproduct and make energy rich compounds ATP and NADPH
What are the light-independent reactions?
(USE CALVIN CYCLE) ATP and NADPH molecules made from Light-dependent reactions are used in light-independent reactions to make sugars from carbon dioxide. Reactions take place outside of thylakoids in the stroma
What is an electron transport chain?
(ETC) - a series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions. These electrons come from water molecules.
(this means water is a limiting factor in the process of photosynthesis)
What is ATP synthase?
a protein that spans the thylakoid membrane and allows H+ ions to pass through it. Powered by the H+ gradient, H+ ions rotate the protein on its route to the other side which adds a Phosphate (P) to ADP to produce ATP.
The trans-membrane protein that makes ATP
What are 3 factors affecting photosynthesis?
Temperature- enzymes involved work best between 0-35d C
Light intensity- positive correlation with an upper limit
Water- need electrons from H20, water is a big limiting factor to photosynthesis
How does photosynthesis work under extreme conditions?
C4 Photosynthesis- have specialized chemical pathway that allows them to capture CO2 for the calvin cycle by first producing a compound to fixate carbon, storing it to be used during times of intense heat and light.
Examples include sugar cane, corn, and sorghum
CAM Plants- adapted to dry climates to obtain carbon dioxide while minimizing water loss. Close stomata during day, open at night. At night, they turn CO2 into Crassulacean Acid. (CAM stands for Crassulacean Acid Metabolism). They metabolize the acid to free up carbon for the calvin cycle during the day instead of having to open the stomata during the day to get CO2. This reduces water lost through transpiration
