Honors Biology Ch. 8 - PowerPoint PPT Presentation

1 / 45
About This Presentation
Title:

Honors Biology Ch. 8

Description:

Honors Biology Ch. 8 Cellular Energy – PowerPoint PPT presentation

Number of Views:174
Avg rating:3.0/5.0
Slides: 46
Provided by: cobb5
Category:

less

Transcript and Presenter's Notes

Title: Honors Biology Ch. 8


1
HonorsBiologyCh. 8
  • Cellular Energy

2
I. How Organisms Obtain Energy
  • - Cells are miniature factories where thousands
    of reactions using energy occur constantly.

3
A. Transformation of Energy
  • 1. First Law of Thermodynamics
  • - Energy cannot be created or destroyed, but can
    be transformed and transferred.

4
2. Second Law of Thermodynamics
  • - When energy is transformed, some energy is lost
    as heat.

5
3. All Organisms Use Energy
  • a. Autotrophs
  • - organisms that make their own food
  • - photosynthesis
  • - producers

6
b. Heterotrophs
  • - organisms that obtain energy from other
    organisms
  • - consumers

7
B. Metabolism
  • - all the chemical reactions in a cell
  • 1. Catabolic Pathways
  • - break down large molecules into smaller
    molecules releasing energy
  • - cellular respiration
  • 2. Anabolic Pathways
  • - build up larger molecules from small
    molecules using energy
  • - photosynthesis

8
C. ATP
  • - adenosine triphosphate
  • - energy transfer molecule
  • - provides energy for cellular functions

9
Energy Flow and Chemical Recycling in Ecosystems
10
II. Photosynthesis
  • - light energy is converted to chemical energy
  • A. Chloroplasts
  • - organelle of photosynthesis

11
B. Photosynthetic Pigments
  • - Pigments are substances that absorb light energy

12
  • - chlorophyll absorbs violet-blue and red light
  • - Chlorophyll a is the primary photosynthetic
    pigment.

13
- Chlorophyll b and carotenoids are accessory
pigments.
Chlorophyll a, Chlorophyll b, and ß - Carotene
are found in plants.
Phycoerythrin is found in red algae
Phycocyanin is found in blue-green algae
14
Photosynthetic Pigments Found in Spinach leaves
15
Molecular Structure of Cellulose
16
C. Light Reactions
  • - Light energy is used to produce ATP and NADPH
    for the Calvin Cycle.

17
C. Light Reactions
  • - Light energy is used to produce ATP and NADPH
    for the Calvin Cycle.

18
1. Light absorbed by Photosystem II
  • - Water molecules are split, oxygen released.
  • - Electron becomes excited and enters electron
    transport chain.

19
2. The Electron Transport Chain
  • - Energy from electrons pumps H into thylakoid
    space as it passes along the electron transport
    chain.

20
3. More Light Absorbed by Photosystem I
  • - Electron becomes re-excited.
  • - NADPH (an electron carrier and energy transport
    molecule) is formed.

21
4. Chemiosmosis
  • - Hydrogen ions (protons) move down their
    concentration gradient out of the thylakoid space.

22
5. ATP Synthase
  • - ATP synthesized by ATP synthase as hydrogen
    ions pass out of the thylakoid space.

23
D. Calvin Cycle
  • - Glucose produced with energy from ATP and NADPH
    from the light reactions.

24
1. Carbon Fixation
  • - 6 CO2 are joined to 6 5-C molecules of RuBP to
    form 12 3-C molecules of PGA.

25
The Calvin Cycle
26
2. G3P Produced
  • - Energy from 12 ATP and 12 NADPH is used to
    produce 12 G3P (glyceraldehyde 3-phosphate)
    molecules.
  • - 2 G3P molecules are used to make glucose.

27
The Calvin Cycle
O2
6
28
3. Calvin Cycle Completed
  • - 6 RuBP molecules produced from 10 G3P molecules
    to complete the Calvin Cycle.

29
The Calvin Cycle
O2
6
30
Alternative Photosynthesis PathwaysC4 and CAM
C4 Photosynthesis
CAM Photosynthesis
CO2
Organic acids release CO2 to Calvin cycle
Organic acids release CO2 to Calvin cycle
31
III. Cellular Respiration
  • - Organic molecules (glucose) are broken down to
    release energy in the form of ATP to do cellular
    work.

32
  • - Occurs in 2 main parts glycolysis and
    aerobic respiration

33
A. Glycolysis
  • - splits glucose (6-C) into pyruvate (3-C) to
    release energy
  • - produces 2 ATP and 2 NADH
  • - occurs in the cytoplasm
  • - does not require oxygen

34
B. Krebs Cycle
  • - completes the energy yielding break down of
    pyruvate
  • - produces (for each glucose) 2 ATP, 6
    NADH, 2 FADH2, and 3 CO2
  • - takes place in the matrix of the
    mitochondrion

35
C. Electron Transport Chain
  • - a series of protein molecules embedded in the
    inner membrane of the mitochondrion
  • - requires oxygen

36
  • - Energy from electrons from NADH and FADH2 pumps
    H ion into the intermembrane space creating a H
    gradient.

37
  • - At the end of the chain, electrons are passed
    to oxygen, forming water.

38
D. Chemiosmosis
  • - H ions move down their concentration gradient
    out of the intermembrane space.
  • - ATP synthesized by ATP Synthase as H
    ions pass out of the intermembrane
    space.

ATP Synthase
39
D. Chemiosmosis
  • - H ions move down their concentration gradient
    out of the intermembrane space.
  • - ATP synthesized by ATP Synthase as H
    ions pass out of the intermembrane
    space.
  • - Produces 32 ATP

ATP Synthase
40
IV. Anaerobic Respiration (Fermentation)
  • - Uses glycolysis to produce ATP in the absence
    of O2.
  • - Regenerates NAD from NADH.
  • - Produces only 2 ATP from glucose.

41
A. Lactic Acid Fermentation
  • - Occurs when skeletal muscles use up O2 faster
    than lungs can supply O2.
  • - Lactic acid produced from pyruvate and NADH
    converted to NAD.

42
  • - Also produced by bacteria when processing milk
    into yogurt and cheese.

43
B. Alcohol Fermentation
  • - Occurs in yeast and some bacteria.
  • - Ethanol and CO2 produced from pyruvate and
    NADH converted to NAD.

44
How Cells Obtain Energy A Review of Cellular
Respiration and Photosynthesis (1402)
45
  • The
  • End
Write a Comment
User Comments (0)
About PowerShow.com