27 terms

Miller and Levine Biology Chapter 8

Photosynthesis
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ATP- Adenosine Triphosphate
A type of bio-chemical fuel. An important compound that cells use to store and release energy. Basic energy source for all cells.
ADP -Adenosine Diphosphate
Looks almost like ATP except it has two phosphate groups instead of three. Works like a rechargeable battery when cells add phosphate groups --> ATP.
Glucose
ATP is great for transferring energy but not storing. Glucose stores 90 x more energy than required to add phosphate group to turn ADP --> ATP.
Heterotrophs
Organisms that get their food by absorbing other living things. (i.e. Plants, animals, decomposers)
Autotrophs
Organisms that make their own food through photosynthesis.
Photosynthesis
The process by which autotrophs use the energy of sunlight to produce high-energy carbohydrates- sugars and starches - that can be used as food. Plants convert energy of sunlight into chemical energy stored in bonds of carbs.
ATP and ADP Structure
ATP has 3 phosphate groups (fully charged battery. ADP has two (partially charged battery)
Sunlight
the ultimate source of energy for plants. Makes all life possible.
Decomposers
considered heterotrophs because they get energy from breaking down other living things - not from the sun.
Pigments
Plants gather the sun's energy with light-absorbing molecules called pigments.
Light
What our eyes perceive as "white" light is a mixture of different wavelengths. ROYGBIV
Chlorophyll
Plants principle pigment used to capture energy from the sun. Chlorophyll a absorbs blue-violet wavelengths and chlorophyll b absorbs red wavelengths. Does not absorb green - reflects.
Chloroplasts
Photosynthesis takes place in organelles called chloroplasts which contain saclike membranes called thylakoids and outside the thylakoids is a fluid portion known as the stroma.
Granum
thylakoids are interconnected and arranged in stacks known as granum. Pigments are in the thylakoid membranes.
Electron carrier
a compound that can accept a pair of high-energy electrons and transfer them, along with most of their energy, to another molecule. (Like mitts moving a hot potato)
NAPD +
Converts to NADPH to trap sunlight as chemical energy. A high energy electron carrier than can move energy to help build molecules like carbs (glucose/sugar and starches)
Photosynthesis (2)
Uses the energy of sunlight to convert water and carbon dioxide (reactants) into high-energy sugars and oxygen (products)
Light Dependent Reactions
First step in photosynthesis - require direct involvement of light and light-absorbing pigments ADP and NADP+ --> ATP and NADPH. Requires water as a source of electrons and hydrogen ions and gives off oxygen as a byproduct.
Light Independent Reactions
ATP and NADPH are used to produce high-energy sugars from carbon dioxide. (No light is required) Takes place in the stroma outside the thylakoids.
Byproduct
Anything produced in the course of making another thing.
Photosystems
thyladoids contain clusters of chlorophyll and proteins known as photosystems which absorb sunlight and generate high-energy electrons.
Electron Transport Chain
a series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions.
Photosystem 1
pigments in photosystem 1 use energy from light to reenergize electrons depleted from pumping H+ ions across the thylakoid membrane.
Photosystem II
hydrogen atoms begin to accumulate in the thylakoid space which makes stroma negatively charged . This gradient (the difference in both charge and H+ ion concentration) provides the energy to make ATP.
ATP Synthase
Spans the thylakoid membrane and allows H+ ions to pass forcing it to rotate like a turbine and produce ATP. Process is known as chemiosmosis.
Calvin Cycle
During the light-independent reactions ATP and NADPH from the light-dependent reactions are used to produce high-energy sugars. Uses 6 molecules of carbon dioxide to produce a single 6-carbon sugar molecule. Removes CO2 from atmosphere.
Factors affecting photosynthesis
temperature, light intensity and the availability of water.