1. Living Metabolism

2. Metabolism
The sum total of all chemical reactions occurring in an organism.
A chemical reaction is a process that changes, or transforms, one set of chemicals into another by changing chemical bonds.

3. Dehydration and Hydrolysis Reactions
Short polymer
Unlinked monomer
Dehydration removes a water
molecule, forming a new bond
Longer polymer
Dehydration reaction in the synthesis of a polymer
Hydrolysis adds a water
molecule, breaking a bond
Hydrolysis of a polymer

4. Remember! Parts of a Reaction
Substrates (a.k.a. Reactants)
Products
Reactants or Substrates enter a chemical reaction and are turned into products

5. Metabolism Movie

6. Two Types of Metabolic Activity
Anabolism
Combining small molecules into larger molecules.
Example: Photosynthesis
Light + 6 CO2 + 6 H2O  C6H12O6 + 6 O2
Reactants
Products

7. Anabolism (Dehydration Synthesis)
Products
Amount of
energy
required
(G > 0)
Free energy
Energy
Reactants
Progress of the reaction
Endergonic reaction: energy required

8. Reactants Products Catabolism
Breaking down large molecules into smaller molecules
Example: Cellular Respiration
C6H12O6 + 6O2  6CO2 + 6H2O + ATP
Reactants
Products

9. Catabolism (Hydrolysis Reaction)
Reactants
Amount of
energy
released
(G < 0)
Free energy
Energy
Products
Progress of the reaction
Exergonic reaction: energy released

10. Photosynthesis and Cellular Respiration are Coupled Chemical Reactions
Light + 6 CO2 + 6 H2O  C6H12O6 + 6 O2
Photosynthesis
C6H12O6 + 6O2  6CO2 + 6H2O + ATP
Cellular Respiration

11. Energy Coupling between Photosynthesis and Cellular Respiration
Light
energy
ECOSYSTEM
Photosynthesis
in chloroplasts
CO2 + H2O
C6H12O6
+ O2
Cellular respiration
in mitochondria
Energy is eventually lost or transformed from a high quality (e.g. electromagnetic radiation) form of E into a low quality (e.g. heat) form of energy. Matter is cycled over and over again in an ecosystem.
ATP
powers most cellular work
Heat
energy

12. Remember!
Photosynthesis and Cellular Respiration are basically the same reaction, only one is the reverse of the other
The materials made by photosynthesis (glucose and oxygen) are the same ones required for respiration
If we write the equation for photosynthesis:
Energy (light) + 6 CO2 + 6 H2O  C6H12O6 + 6 O2
We can rearrange it to make the equation for cellular respiration:
C6H12O6 + 6O2  6CO2 + 6H2O + Energy (ATP)

13. Where does photosynthesis happen?
Chloroplasts

14. Where are chloroplasts?
In plant leaves and stems

15. Chloroplasts in plant leaf cells

16. What color are chloroplasts? Why?
Green
Because they contain a green pigment called chlorophyll

17. Fun Fact: Why is chlorophyll green?
Because it doesn’t absorb wavelengths of light between nm very well
In other words, it reflects green light

18. Absorption vs. Reflection
There are 2 photosystems located in thylakoid membranes

19. Electromagnetic Spectrum

20. Chloroplasts absorbing the blue and the red light waves
Chloroplasts absorbing the blue and the red light waves. The green is NOT being absorbed.

21. Fun Facts: How long is a nanometer?

22. Chlorophyll is a pigment that absorbs light energy in order for photosynthesis to occur.
Energy (light) + 6 CO2 + 6 H2O  C6H12O6 + 6 O2
Reactants
Products

23. What happens to the glucose made in photosynthesis?
Some is stored as starch (anabolism)
Some is broken down to make ATP (catabolism)

24. Carbohydrate Digestion in Humans
Begins in the Mouth: Mechanical & Chemical Digestion
Mechanical: physically break food into smaller pieces
Chemical: chemically change the food, e.g. starch is converted into maltose
In the mouth, food is mixed with saliva which breaks down complex carbs into simple carbs. The enzyme alpha amylase catalyzes the hydrolysis of starch into maltose

25. Alpha Amylase & Maltase
The salivary glands produce an enzyme called amylase that catalyzes the hydrolysis of starch (a polysaccharide) into maltose (a disaccharide).
The sm. Intestine produces an enzyme called maltase that catalyzes the hydrolysis of maltose into glucose (a monosaccharide)
Remember: enzyme names end with ase and sugar names end with ose
FYI: People who are lactose intolerant do no produce lactase (responsible for hydrolyzing lactose into glucose and galactose). Lactase is produced in high amounts by mammals to help them digest milk sugars. It’s usually produced less after weaning (a single mutation that occurred 5-10 thousand years ago allows the enzyme to be made throughout life. If lactose passes into the lg. intestine undigested, intestinal bacteria begin to ferment the lactose, resulting in the production of methane, CO2 and hydrogen sulfide. The symptoms are gas, bloating, and diarrhea. These people can take Lactaid (an enzyme supplement) to help reduce symptoms.

26. Where does the glucose go?
It’s absorbed through the walls of your sm. intestine, dumped into your blood stream and then transported to every cell in your body.
Where does the glucose go once in the cell?
Mitochondria

27. What happens in the mitochondria? Why?
Cellular Respiration
C6H12O6 + 6O2  6CO2 + 6H2O + ATP
The purpose of cellular respiration is to make ATP
Since this type of cellular respiration requires O2, it is called aerobic respiration (Glycolysis, Krebs Cycle, Electron Transport Chain)
Reactants
Products
What is cellular respiration? Glycolysis (cytoplasm 2 ATP), Krebs Cycle (matrix 2 ATP), Electron Transport Chain (inner mitochondrial membrane ATP)

28. The Process of Cellular Respiration
Glucose is a 6 C molecule. Glycolysis splits glucose into two 3 C molecules (pyruvate or pyruvic acid)
Glycolysis 2 ATP, Krebs 2 ATP, ETC ATP

29. ATP ATP or Adenosine triphosphate is the energy molecule of the cell
ATP carries a form of potential E in the bond between its 2nd and 3rd phosphates

30. ATP Structure
Ribose Sugar
Nitrogen Base: Adenine
Phosphate (x3)

31. ATP Function ATP provides the energy cells need to do work
Mechanical work: ATP phosphorylates motor proteins
Transport work: ATP phosphorylates transport proteins
Chemical work: ATP phosphorylates key reactants

32. How do cells make ATP without O2?
When there isn’t enough O2 for aerobic cellular respiration, your cells use anaerobic cellular respiration (glycolysis, fermentation) to produce ATP
Fermentation
Lactic Acid or Alcoholic
Interesting Fact: the build up of lactic acid causes your muscles to burn during intense exercise.
Anaerobic Respiration = Gylcolysis + Fermentation

33. Autotroph
Organisms that are able to produce their own food through photosynthesis are called autotrophs
Photo “light” synthesis “putting together”
Auto “self” troph “food”
Autotrophs make carbs that serve as food for them and almost all other organisms on earth

34. Autotroph - Plants

35. Autotroph - Phytoplankton

36. Autotroph - Bacteria

37. Heterotroph
Organisms that are not able to make their own food are called heterotrophs
Hetero “other” troph “food”
Heterotrophs consume other organisms or parts of other organisms for food.

38. Heterotroph - Animal

39. Heterotroph - Fungus

40. Remember!
Autotrophs can make their own food (glucose), but they still have to break it down to make ATP
Heterotrophs cannot make their own food, which means they gave to get the glucose they need by eating other organisms. Then they can break the glucose down to make ATP
This means that BOTH autotrophs and heterotrophs use cellular respiration in order to break down glucose and make ATP