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Section 4-1. Chemical Energy and ATP. Organisms are classified according to their energy usage:. Autotrophs – make their own food. Ex. Plants & algae. ATP is Adenosine Triphosphate. ATP is the energy molecule used by the cell. Chemical Structure of ATP. Adenine - Nitrogen Base.
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Section 4-1 Chemical Energy and ATP
Organisms are classified according to their energy usage: • Autotrophs– make their own food. • Ex. Plants & algae
ATP is Adenosine Triphosphate ATP is the energy molecule used by the cell.
Chemical Structure of ATP Adenine- Nitrogen Base 3 Phosphates (tri = 3) Ribose: 5-carbon Sugar
ADP • Adenosine Diphosphate is ADP • ADP has the same structure as ATP, except it only has 2 phosphates.
ATP Facts • ATP is good to transfer energy in the cell, but not to store energy. • Cells depend on the sugar, glucose, for stored energy. • Cells then convert glucose into ATP as needed.
Section 4-2 Photosynthesis Overview
Photosynthesis Defined • Plants use energy from sunlight to convert water and CO2into glucose, releasing oxygen as a by-product. • The chemical equation of photosynthesis is: Light 6CO2 + 6H2O → C6H12O6 + 6O2
Requirements of photosynthesis • Pigments are light absorbing compounds. Some are found in plant leaves and stems. • Chlorophyll is a pigment that absorbs light energy. • In plants, chlorophyll is found in organelles called chloroplasts.
Section 4-2 Overview of Photosynthesis
Photosynthesis takes place in the chloroplasts of the plant cell. • A chloroplast has two primary areas. • Grana are stacks of thylakoid membranes. • Stroma is the fluid surrounding the membranes.
Two Stages of Photosynthesis • Light-dependent reactions- need light and occur in the grana and thylakoid membranesof the chloroplast. • Light-independent reactions- does not need light and occurs in the stroma. (AKA – the Calvin Cycle)
Light Dependent Reactions • take place in thylakoids • water and sunlight are needed • chlorophyll absorbs energy • energy is transferred along thylakoid membrane then to light-independent reactions • oxygen is released
The END PRODUCTS of the light reactions • NADPH • ATP • Oxygen (released)
Light Independent Reactions • take place in stroma • needs carbon dioxide from atmosphere • use energy to build a sugar in a cycle of chemical reactions
The END PRODUCTS of the light independent reactions • Sugar (C6H12O6)