Plant Cells & Energy Production Flashcards
Can produce food from substances in their external environment (such as light) to generate ATP.
Can obtain energy directly from their environment.
Plants and some protists —> Capable of generating chemical energy from sunlight.
Autotrophs
Can’t produce their own food and obtain nutrition from other organisms. —> Obtain energy/nutrition by/from consuming other organisms.
Humans and other energy —> Must ingest (eat) other organisms (such as plants or animals) to obtain energy and keep making ATP.
Heterotrophs
A phosphate group can be cleaved off the ATP via this process.
Bond-breaking through the addition of water releases chemical energy.
Hydrolysis
Recycling of ADP into ATP & the breakdown of ATP into ADP.
ATP/ADP Cycle
Phosphate group added on to ADP (to form ATP).
Phosphorylated
The ability of plants to convert carbon dioxide into glucose using sunlight.
Overall reaction: carbon dioxide, water, and light react to form sugar (glucose) and oxygen.
Photosynthesis
Triggered by photons of light striking chlorophyll.
Light-Dependent Reactions
Take place after an electron has been liberated.
Light-Independent Reactions
Light hits molecules in _________, which excites and electron. Loss of the high-energy electron leaves the chlorophyll unstable and in need of a low-energy electron, which it gets from water (liberating hydrogen and forming oxygen).
First part of photosynthesis.
Photosystem II
The photoexcited electrons are carried via an electron transport chain to ___________. The electron transport chain generates ATP, more light energizes the chlorophyll molecules, the energized electrons enter another electron transport chain, which reduces NADP+ to NADPH.
Part of photosynthesis.
Photosystem I
ATP and NADPH created by the light-dependent reactions are used in the next step. —> Light-independent.
An enzyme (RuBisCO) adds carbon dioxide to a 5-carbon molecule (RuBP) to form 2 molecules of the 3-carbon molecule (G3P). —> Carbon fixation. ATP and NADPH are used to produce G3P and to regenerate RuBP to allow carbon fixation. —> 3 rounds of this cycle are required to fix 3 carbon dioxide molecules (allowing 1 molecule of G3P to be exported —> G3P is then used to make glucose, starch, or cellulose).
Last part of photosynthesis.
Calvin Cycle
Takes place in the thylakoid membranes (inside the chloroplasts) and require the presence of light to occur.
Photosystem II then Photosystem I.
Light-Dependent Reactions
Don’t require the presence of light to occur and are made up by the Calvin Cycle.
Light-Independent Reactions
Require light and require water molecules (that are broken down into parts).
Occur when light strikes the chlorophyll (contained in the chloroplast)
Make ATP and NADPH, which are used to fuel light-independent reactions.
Light-Dependent Reactions
Light-Dependent Reactions
Photosystem II and Photosystem I
Light-Independent Reaction
Calvin Cycle
Water is broken down into H+ ions, oxygen, and electrons (the oxygen is released as a waste product).
H+ ions build up inside the thylakoid space. —> The energy from light is absorbed into the chlorophyll and is used to energize electrons. —> The energized electrons get passed through a series of molecules called the electron transport chain (end result = pumping more H+ ions inside the thylakoid membrane, which makes pressure).
As the H+ ions leave the thylakoid space, they go through a protein on the membrane that acts like a machine for making ATP (every time an H+ ion leaves, it cranks the machine and ATP is made).
Photosystem II
The electrons get hit with more light and are energized again. —> They go through another electron transport chain that creates NADPH.
Photosystem I
The plant takes in carbon dioxide.
Using energy from ATP and NADPH, it builds energy-rich carbohydrates (3-carbon compounds) that can become sugars. —> Some of these leave the cycle to be turned into sugars, others stay to be part of the machinery that makes more 3-carbon compounds). —> They continue going through a cycle that allows them to keep being reused to build more 3-carbon compounds (as long as there is a supply of ATP and NADPH to provide the energy).
Has to happen 6 times to make 1 glucose molecule.
Calvin Cycle
