1. Energy and Element Flow in Ecosystems
Semester 1: Unit 2:
Energy and Element Flow in Ecosystems

2. MACROMOLECULES (Biological Molecules)

3. Crash Course: Biological Molecules

4. What’s the deal with carbon?
Carbon is essential to life! Our bodies are made up of thousands of carbon- containing molecules called Organic molecules! Organic molecules = Contain the element Carbon!!

5. Macromolecules Organic Molecules are called Macromolecules
Carbohydrates
Lipids
Proteins
Nucleic Acids
Organic molecules are built using building blocks called MONOMERS
Mono: 1
When you put together those building blocks you build large organic molecules called POLYMERS
Poly: many

6. Carbohydrates
Chapter 2

7. Carbohydrate Purpose
Carbohydrates are SUGARS made of carbon, hydrogen, and oxygen atoms in a 1:2:1 ratio
Function: Carbohydrates provide energy for the brain and ½ of energy for muscles and tissue
Carbs are not equal
Simple Carbohydrates: Sources for Instant energy (Monosaccharides)
Complex carbohydrates: Store houses for energy (Polysaccharides)

8. Simple Carbohydrates (simple sugars)
Monosaccharides (monomers)
Glucose: essential energy source
Fructose: the sweetest, occurs naturally in honey & fruits. Added to many foods in the form of high fructose corn syrup.

9. Complex Carbohydrates
Polysaccharides (Polymers)
Glycogen
Starch
Cellulose

10. Complex Carbohydrates: Glycogen
For humans & animals, after we eat, whatever energy (glucose) is not used right away is stored as glycogen.
Good for short term storage (~1 day)
Stored in muscles & the liver

11. Complex Carbohydrates: Starch
Plants store LOTS of energy, in the form of starch.
When humans eat plants we take in this energy.
Most common carbohydrate in our diet.

12. Complex Carbohydrates: Cellulose
Cellulose is the main building material for plant cell walls.
Plants are made of this complex carbohydrate.
When humans eat plants, cellulose is not easily digested.
Animals digest cellulose more easily.

13. How do we store energy more long term?
So for humans…. if even the biggest carbohydrate (glycogen) only stores energy for about 1 day….
How do we store energy more long term?
FAT! = Lipids

14. Lipids
Chapter 2

15. Lipid Purpose Lipids are made of carbon, hydrogen & oxygen
-Just like carbs
-Why carbs easily turn to fat
Function:
Store energy long term, and make cell membranes.
Have more bonds than carbs = more energy storage
Examples: Fats, waxes, cholesterol, oils

16. Lipid Structure Lipid MONOMERS are made of two parts:
3 Fatty acid chains linked to
3 glycerol groups
Lipids are not equal
Saturated
Unsaturated
GLYCEROL
FATTY ACID CHAIN

17. UNsaturated Lipids Saturated Lipids
Unsaturated Lipids have one or more double bonds in its fatty acid chain, creating a kink in the chain
Saturated Lipids have ONLY SINGLE BONDS in its fatty acid chain
FATTY ACID CHAIN
Tend to be liquid (oils)
chains can’t stack close together because of kink in chain
tend to be solids
chains can stack closer together

18. Lipid Characteristics
Lipids are also waterproof molecules because they have non-polar bonds (equal sharing of electrons)
Think of oil & water!
They don’t mix!
WATER
REPELLENT
TAIL

19. Proteins
Chapter 2

20. Our bodies contain thousands of proteins keeping you alive!
Purpose of proteins
Proteins do LOTS of things in your body
Our bodies contain thousands of proteins keeping you alive!
Enzymes – regulating chemical processes and helping you digest food
Antibodies – protecting your body from bacteria
Endorphins – proteins in your brain that make you feel emotions

21. Protein Structure Chains of amino acids = Polypeptide Chains
Monomer = Amino Acid
Chains of amino acids = Polypeptide Chains
Polymer = Protein

22. Amino acids are the building blocks (monomers) of Proteins!
The “R” group is where one of twenty different side chains can attach, making twenty different amino acids – which will determine the protein’s function.

23. Building proteins from amino acids
Amino acids bond together through peptide bonds.
Peptide bonds
Condensation reaction between two amino acids
Produces H2O as a by-product
A chain of amino acids is a polypeptide.
NOTE** This is the first time that nitrogen has shown up!

24. Importance of Nitrogen
Nitrogen is one of the most abundant chemicals on earth
all around us in the atmosphere and in the air we breathe.
We can’t use nitrogen gas
Must eat it to use it!

25. Nucleic Acids
Chapter 2

26. Purpose of Nucleic Acids
Nucleic Acids form and transmit genetic information by making proteins. Nucleic acids are your DNA and RNA! Genetic information is passed down to new cells during the process of MITOSIS or cell splitting.

27. Structure of Nucleic Acids
Nucleic acids are made up of pieces (monomers) called Nucleotides.
Each Nucleotide has 3 parts:
Deoxyribose (5-carbon sugar)
Phosphate Group
Only Macromolecule containing phosphorous
Nitrogen Base
It’s the combination of these nucleotides that make up an entire dna or rna strand!
Nucleotide Structure

28. Macromolecules Summary

29. What is in each Macromolecule?
C H O N P
Carbon Hydrogen Oxygen Nitrogen Phosphorus
Lipid
Carbs.
Protein
Nucleic
Acids

30. What do you know? What happens to the food you eat?
What is a chemical reaction?

31. Chemical Reactions
A chemical reaction is a process that changes one set of chemicals into another.
Reactants: Compounds/Elements that enter the reaction
Products: Compounds/Elements that are produced by the reaction

32. Reactions involve changes in bonds between atoms
*bonds break = energy is released
*bonds made = energy is absorbed/stored
-The more bonds something has the more energy it has stored

33. How Biomolecules are used in the body
The food you eat is rearranged via chemical reactions
Broken into C,H,O,N,P
Those atoms are used to make new molecules the body needs

34. What is an enzyme? Enzymes
-help chemical reactions run more efficiently
-proteins that act as catalysts.
-speed up chemical reactions
-breakdown food during digestion
-break polymers in food into their monomers

35. Lactose Intolerance
Lack of a specific enzyme (lactase) that breaks down lactose sugar in milk into smaller monomers leads to lactose-intolerance

36. How do enzymes work? Enzymes are known as “catalysts”.
Catalysts speed up chemical reactions by lowering the “activation energy” to get a reaction started.
It takes lots of energy to get a reaction started.
Having a catalyst present allows less energy to be used to get a reaction started.

37. Catalysts (enzymes) help chemical reactions happen with less energy.

38. Enzyme productivity
In order for enzymes to work efficiently, they have to be in the right environment.
There are some things that affect how well enzymes work. They are:
Temperature
pH (acid or base)
Activators & Inhibitors (supplements, drugs, poisons, etc)

39. Temperature effects enzyme activity
Each enzyme has its own optimum temperature
pH (acidity) effects enzyme activity
Each enzyme has its own optimum pH

40. At what pH do both enzymes have the same activity?
Which enzyme has an optimum pH of around 6.5?

41. Obtaining and Using Energy

42. What do you know? What is energy? What do you need energy for?
How does your body use/store energy?

43. What is energy?

44. Energy is the ability to do work.
Without ability to obtain & use energy, life would NOT exist.
One of the most important compounds that cells use to store & release energy is adenosine triphosphate (ATP).

45. ATP consists of:
-adenine (nitrogenous base)
-a 5-carbon sugar called ribose
- three phosphate groups

46. ATP can easily release and store energy by breaking and re-forming the bonds between its phosphate groups.
This characteristic makes ATP very useful as a basic energy source for cells

47. Storing Energy
Adenosine diphosphate (ADP) -has 2 phosphate groups instead of 3.
-contains some energy (not as much as ATP)
When a cell has energy available, it stores small amounts by adding a phosphate group to ADP, making ATP.
ADP is like a rechargeable battery that powers the cell.

48. Releasing Energy
Cells release the energy stored in ATP by breaking the bonds between the 2nd & 3rd phosphate groups.
A cell can add (+) or subtract (-) these phosphate groups giving it an easy way of storing & releasing energy as needed.

49. Storing Energy
*ADP into ATP=
stored energy
(fully charged
battery)

50. Intro to Photosynthesis

51. Types of Organisms
Autotrophs- organisms that make their own food (carry out photosynthesis)
Ex: plants, algae, some bacteria
Heterotrophs- organisms that obtain food by consuming other living things
Ex: humans, insects, cheetah, mushroom, etc

52. Photosynthesis During photosynthesis-
organisms convert energy from sunlight into chemical energy stored in the bonds of carbohydrates.

53. Energy from the sun travels to Earth in the form of light
Sunlight is a mixture of different wavelengths & make up a color spectrum. (ROYGBIV)

54. Plants gather the sun’s energy with light-absorbing molecules- pigments.
plants’ main pigment is chlorophyll
2 types in plants: - chlorophyll a
- chlorophyll b
Both chlorophylls absorb light in the blue- violet & red regions of the spectrum

55. Green plants do NOT absorb in the green region
have chlorophyll b which reflects green light, which is why plants look green.

56. Red plants do NOT absorb in the red region
have chlorophyll a which reflects red light, which is why plants look red.

57. Why to leaves change in the fall?
Leaves turn red from green during the fall because chlorophyll b breaks down, leaving other pigments to show their colors

58. Photosynthesis uses the energy of sunlight to convert water & carbon dioxide into high-energy sugars & oxygen.

59. Photosynthesis involves 2 reactions sets:
1- light-dependent reactions
2- light-independent reactions (Calvin cycle)

60. Light-Dependent Reactions:
Water & light energy = in
Oxygen, ATP, & NADPH = out

61. Light-Independent Reactions (Calvin cycle):
CO2, ATP & NADPH = in
high energy sugars/carbohydrates = out

62. Factors Affecting Photosynthesis
The main factors that affect photosynthesis are:
Temperature
Light intensity
Availability of water
Availability of Carbon Dioxide

63. Temperature:
photosynthesis reactions are due to enzymes that function between 0°C & 35°C
Temps above or below that range may slow down the rate of photosynthesis or stop it entirely.

64. Light: High light intensity increases rate of PS.
After light intensity reaches a certain level, plants reach the maximum rate of PS.

65. Water: Water shortage can slow or stop PS.
Water loss can also damage plant tissues.
Plants living in dry conditions have waxy coatings on leaves to reduce water loss.
Too much water can drown plants

66. Carbon Dioxide: More CO2 = Higher rate of photosynthesis
No CO2 = No photosynthesis

67. Which scenario would result in the most plant growth?
Put two together:
Explain this chart in terms of both light intensity and CO2 availability
Which scenario would result in the most plant growth?

68. Intro to Cellular Respiration

69. Cellular Respiration

70. Heterotrophs get energy from food.
Food molecules release chemical energy when chemical bonds break.
Cells break down food & use the stored energy to produce ATP to power the cell’s activities.
Happens in ALL organisms (even autotrophs)
cellular respiration gives cells energy in a usable form.

71. Occurs in the mitochondria of a cell Chemical equation (symbols):
Cellular respiration- releases energy from food in the presence of oxygen.
Occurs in the mitochondria of a cell
Chemical equation (symbols):
6 O2 + C6H12O6  6 CO2 + 6 H2O + Energy
In words:
Oxygen + Glucose Carbon dioxide + Water + Energy

72. Cellular Respiration: 3 stages (in order) are: 1- Glycolysis
2- Krebs cycle
3- Electron Transport
Chain (ETC)
Why you breathe O2

73. Cellular Respiration:
Glycolysis: 2 ATP
Citric Acid: 2 ATP
ETC: 34 ATP
NET GAIN per Gluose = 36 ATP

74. What do you notice about PS and CR?
They are opposites!

75. Photosynthesis & cellular respiration are opposite processes.
PS removes CO2 from the air; CR returns it.
PS releases O2 into the air; CR uses O2 from air to release energy from food.
PS “deposits” energy & CR “withdraws” it.
The reactants of CR are the products of PS & vice versa.

76. Release of energy by
cellular respiration-
in plants, animals,
fungi, protists, most
bacteria.
Energy capture by
photosynthesis-
in plants, algae,
& some bacteria.

77. Intro to Fermentation

78. Fermentation

79. Aerobic- process that requires oxygen
Krebs cycle & ETC are aerobic processes.
Krebs & ETC take place inside the mitochondria.
Anaerobic- does not require oxygen
Glycolysis is an anaerobic process.
Glycolysis takes place in the cytoplasm.

80. -Alcoholic Fermentation -Lactic Acid Fermentation
Fermentation - energy is released from food molecules in the absence of oxygen.
occurs in the cytoplasm of cells.
2 types of Fermentation exist:
-Alcoholic Fermentation
-Lactic Acid Fermentation
Under anaerobic conditions, fermentation follows glycolysis.

81. Alcoholic Fermentation:
Yeast & a few other microorganisms use alcoholic fermentation to produce ethyl alcohol & carbon dioxide.
used to produce alcoholic beverages & causes bread dough to rise.
Chemical equation:
Glucose→ Pyruvic acid + NADH  Alcohol + CO2 + NAD+

82. Lactic Acid Fermentation
Carried out best by human muscle cells under oxygen deprivation.
Lactic Acid is a toxin and causes fatigue, soreness and stiffness in muscles that have been overworked.
Chemical equation:
Glucose → Pyruvic acid + NADH  Lactic acid + NAD+

83. Lactic Acid & Exercise
For this sudden burst of energy, cells use the small amount of ATP they can normally conserve. This supply runs out in seconds.
Then fermentation kicks in to produce more ATP for energy, producing lactic acid as a byproduct.
With the build up of lactic acid in the body system the only way to get rid of it is adding LOTS of oxygen.
This is why heavy breathing is necessary after a race!

84. During fermentation, cells convert NADH made by glycolysis back into the electron carrier NAD+, allowing glycolysis to continue producing ATP.

85. Energy Flow
We’ve learned how energy gets into the cycle of life and used by organisms, but how does it move between living things? How do you think it works? How does an insect get energy? How does a wolf get energy?

86. Intro to Energy Flow

87. Sunlight is the ultimate energy source
Consider This:
Where does the electrical energy needed to power the lights in this room come from? What do you think?
How it works:
Electricity is generated at a thermal power plant by burning coal.
What is coal? A fossil fuel!
Fossil fuels are literally highly pressurized remains of dinosaurs/ancient organisms
Where did the dinosaurs get their energy? Eating plants!
Where did the plants get their energy? The SUN!!!

88. Types of Organisms in an Ecosystem
Autotrophs - capture energy from sunlight or chemicals & convert it into forms that living cells use (primary producers).
Use Photosynthesis
Primary Productivity- rate at which primary producers create organic material.

89. Types of Organisms in an Ecosystem
Heterotrophs (consumers)- get energy & nutrients by ingesting other organisms
Decomposers- Decomposers break down material and make it available for producers to use. (Type of heterotroph)

90. Energy flows in one direction in an ecosystem:
producers → consumers
food chain- series of steps in which organisms transfer energy by eating & being eaten.
food web- all food chains in an ecosystem

92. Pyramid of Energy:
most of the energy used on life processes
Remaining energy released as heat
ONLY 10% of the energy available from 1 level is transferred to the next level.

93. Ex: many insects graze on 1 tree: lots of biomass, 1 organism.
Pyramids of Biomass or Numbers:
At times, consumers are smaller in size than the organisms they feed upon.
Ex: many insects graze on 1 tree: lots of biomass, 1 organism.
pyramid of numbers may be upside down

94. Intro to Nutrient Cycles

95. Nutrient Cycles
nutrients- chemical substances organism needs to sustain life
limiting nutrient -nutrient whose supply limits productivity because it is scarce or cycles slow

96. Unlike the 1-way flow of energy, matter (nutrients) are recycled within & between ecosystems.
biogeochemical cycles- pass elements from 1 organism to another & through the biosphere due to energy
matter involved in biological processes, geological processes, & chemical processes.
**Matter is never created or destroyed, only changed!

97. The Carbon Cycle:
Plants take in CO2, build carbohydrates, & pass it through food webs
animals release CO2 by respiration
organisms die, decomposers break them down, & release C in environment
Geologic forces turn C into fossil fuels/rock
The Ocean absorbs a lot of the C in the atmosphere

98. The Carbon Cycle:
C enters atmosphere by volcano & human- activity- burning of fossil fuels, forests