1. The Greenhouse Effect, Cellular Respiration, and Photosynthesis
Is the Earth Warming?
The Greenhouse Effect, Cellular Respiration, and Photosynthesis
Copyright © 2007 Pearson Prentice Hall, Inc.

2. 4.1 The Greenhouse Effect Methane Nitrous oxide Water vapor
The greenhouse effect, the accumulation of specific gases:
Methane
Nitrous oxide
Water vapor
Carbon dioxide (CO2)
Less heat escapes to space
More heat remains in the atmosphere

3. The Greenhouse Effect
It is important to have some greenhouse gases in the atmosphere
If not, all the heat would escape and the planet would be too cold to support life
Cars, trucks, power plants and factories all emit air pollution that forms ground-level ozone or smog.
Many popular consumer products like air conditioners and refrigerators involve CFCs or halons during either manufacture or use. These chemicals damage the earth's protective ozone layer.

4. Water, Heat, and Temperature
Heat is the total amount of energy associated with the movement of atoms and molecules in a substance
Temperature is the intensity of heat
Hydrogen bonds between water molecules are constantly breaking (absorbing heat) and reforming (releasing heat)
Bodies of water absorb heat and keep temperatures stable
Water’s high heat absorbing capacity has important effects on Earths’s climate

5. Carbon Dioxide
The oceans act as the largest heat and carbon dioxide reservoir
But scientists question how much more can they hold
Human activities have caused an increase in levels of carbon dioxide
Mainly from burning fossil fuels

6. The Greenhouse Effect, Organisms, and Their Environment
Has human activity affected the natural cycle of temperature on Earth?
The effects of warmer temperatures are numerous…

7. The Greenhouse Effect, Organisms, and Their Environment
Glacier National Park, Montana
Glaciers are shrinking and disappearing
From 150 glaciers in 1850 to 35 glaciers in 2005
Greenland icecap is thinner every year
Many ice shelves have collapsed in Antarctica

8. Mount Kilimanjaro in Tanzania has lost 82% of its ice cap since 1912

9. The Greenhouse Effect, Organisms, and Their Environment
Effects on climate:
Sea levels rose 4-8 inches in the 20th century due to melting ice
Increases in rain and snow
Increases in storms (frequency and severity)

10. Identify 3 greenhouse gases
Methane
Carbon dioxide
Nitrous oxide

11. What is the main contributer of carbon dioxide to the atmosphere?
Burning of fossil fuels

12. What are the main consequences of the greenhouse effect?
Melting ice caps
Sea levels rising
More severe storms

13. Carbon Dioxide atmosphere bodies of water soil
CO2 is recycled between:
plants and animals
atmosphere
bodies of water
soil
Carbon Dioxide

14. Carbon Dioxide
Plants use energy from sunlight to produce organic molecules by the process of photosynthesis
Photosynthesis take energy from the sun and turn it into energy in food
Photosynthesis also releases oxygen (O2) into the atmosphere

15. Carbon Dioxide
In cellular respiration, plants and animals harvest energy from food and put it into ATP
The metabolism of organic molecules by cellular respiration produces energy and water, as well as CO2, which is put into the atmosphere

16. 4.2 Cellular Respiration
Cellular respiration converts energy stored in chemical bonds into energy used by cells
Cells use ATP (adenosine triphosphate) as their energy source
ATP can supply energy to cells because it stores energy obtained from food

17. The Structure of ATP
A nucleotide made up of an adenine (base), sugar, and three negatively-charged phosphates
The negative charges repel each other, contributing to the stored energy of ATP

18. The Structure of ATP
When ATP (adenosine triphosphate) releases a phosphate, it becomes ADP (adenosine diphosphate)
The phosphate released from ATP can be donated to another molecule (such as an enzyme) in a process called phosphorylation…

19. The Functions of ATP ATP helps carry out many functions in cells:
Mechanical work − such as the movement of proteins in muscles
Transport work − such as the movement of substances across membranes
Chemical work − such as making complex molecules out of simple molecules

20. An ATP molecule is made up of 3 parts:
Sugar
3 phosphate groups
adenine

21. Identify 3 functions of ATP
Mechanical work
Transport work
Chemical work

22. When ATP ____________ another molecule it becomes ____.
Phosphorylates
ADP

23. Cellular Respiration
ATP is in high demand and is regenerated from ADP through cellular respiration
Figure 4.13 Regenerating ATP.
ATP is regenerated from ADP and phosphate during the process of cellular respiration.

24. Cellular Respiration
Cellular respiration (also called aerobic respiration) requires oxygen
Humans breathe in to supply oxygen to their cells
Exhalation gives off carbon dioxide, a waste product of respiration

25. A General Overview of Cellular Respiration
All food is broken down to produce ATP
The equation for carbohydrate breakdown:

26. The 3 steps of cellular respiration are:
Glycolysis
The Krebs cycle
Electron Transport

27. Glycolysis
A 6-carbon glucose molecule is broken down into two 3-carbon pyruvic acid molecules
Occurs in the cytosol
Does not require oxygen (anaerobic)
Makes very little ATP (2)

28. Glycolysis
After glycolysis, the two 3-carbon pyruvic acid molecules move into the mitochondria
Mitochondria are organelles found in all eukaryotes (protist, fungi, plant, and animal cells)

29. The molecules move across the two mitochondrial membranes and into the matrix of the mitochondrion where the Krebs cycle begins
Krebs Cycle

30. Krebs Cycle Where is the energy? The energy from the food is:
Directly put into ATP
Or:
Put into transport molecules
NADH
FADH2

31. The Electron Transport Chain
Series of proteins in the inner mitochondrial membrane
Passes electrons down the chain and are picked up by oxygen
As this occurs, H+ ions are pulled across the membrane into the inner membrane space
Figure 4.21 The electron transport chain.
Energy from electrons added to the top of the electron transport chain is used to produce ATP.

32. Each molecule of glucose is broken down, resulting in carbon dioxide and water and ATP energy

33. Metabolism of Other Nutrients
Proteins and fats are also food molecules that contain energy
They are broken down, but not in exactly the same steps

34. Fermentation Anaerobic process
Series of ATP producing reactions that do not require oxygen
Glycolysis breaks down glucose into molecules of pyruvic acid and produces two molecules of ATP
If sufficient oxygen is present, pyruvic acid formed by glycolysis enters aerobic respiration pathways producing a large amount of ATP
If oxygen levels are low:
Animals pyruvic acid is converted to lactic acid which is carried away by the blood
Bacteria/yeast pyruvic acid is converted to ethanol and carbon dioxide
Anaerobic respiration can provide enough energy for about 30 to 40 seconds of muscle activity

36. Global Warming and Cellular Respiration
Increased global temperatures speed up the life cycle of the spruce bark beetle
Beetles bore holes in bark of spruce trees causing the spruce trees to die
Without cold winters, the spruce bark beetles continue to multiply
Warmer temperatures make enzymes work faster, so metabolic processes work faster; beetles mature twice as quickly
More beetles means more dead trees, which increases forest fires releasing CO2 in the air and heat into the atmosphere

37. List the 3 steps of cellular respiration and identify where each takes place:
Glycolysis; cytosol
Krebs Cycle: mitochondrial matrix
Electron Transport chain: inner membrane of mitochondria

38. Identify the products of glycolysis?
2 pyruvate molecules
NADH
2 ATP

39. Identify the products of the Kreb Cycle:
2 ATP
Carbon dioxide
2 NADH

40. What are the products of electron transport chain?
34 – 36 ATP
Water

41. What is the final electron acceptor in the electron transport chain?
Oxygen