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Experiments

• _Components of an

experiment

– Independent Variable- what you change (x-axis)

– Dependent Variable- what you measure (y-axis)

– Control Group- the group that you

compare your results do. This group is not affected by the IV

• Experimental group(s)- those groups that are changed by the experimenter

Interaction Organism 1 Organism 2

Predation

Mutualism

Commensalism

Why don’t populations grow

forever?

• The number of organisms that can be supported and sustained in a given ecosystem.

•

_{The carrying capacity}

is determined by the

environmental

limiting factors

• Aka, the population size is limited by the limiting factors – the carrying capacity is the populating limit



Carrying

How do organisms obtain energy?

• Autotrophs are producers: make their own food in order to get energy

– Autotrophs perform photosynthesis or chemosynthesis

– This means that nearly all producers are plants and algae

• Heterotrophs are consumers: must consume eat) food to get energy

• Decomposers break down and absorb nutrients from dead organisms

 Autotrophs

and

The arrows show the

direction in which the

Trophic Levels

• The first trophic level = producers

• Second trophic level = primary consumers (herbivores)

• Third trophic level = secondary consumer (carnivore)

• _{Fourth trophic level = tertiary}

Energy and Trophic Levels

• Energy and

Trophic Levels • Only 10% of the energy is passed to the next trophic level. The other 90% is used for metabolism or lost as heat

Energy Pyramid

• Energy Pyramid: Shows how the

energy decrease at

each trophic level as it moves up the

pyramid.

– The total energy transfer from one trophic level to the next is only 10%

Biomass Pyramid

• _Biomass Pyramid: Shows the

weight of the living material at each trophic level

Numbers Pyramid

• _{A numbers pyramid}

represents population size within a tropic

level

• Biomagnification is the increase in concentration of a substance in the

environment

– This is a result of constant pollution

and/or the environment being unable to break down a substance

This a direct result human activity Here in South Florida, Mercury is

accumulating to dangerous levels – can result in vision, hearing, coordination, or speech impairment. In high doses, it can cause mental retardation

 Human

Impact on the

• _{Eutrophication is the} increase in living

organisms in water

–This is often caused by overuse of fertilizer

–This is a direct result runoff from agriculture

–This decreases the

nutrients available to the natural species

 Human

Impact on the

• Deforestation: the destruction of a forest

– the cleared area is not replaced with a forest

– Loss of habitat, increase in atmospheric CO2

• Invasive Species: the introduction of non-natural species to ecosystems

– the new species disturbs the delicate ecosystem

• Oil Spills: when oil is spilled or leaked into the ocean, it causes serious harm to the environment

• When we remove nutrients from an ecosystem, species will likely go extinct

– This means the balance of the ecosystem is thrown off -- > this is BAD

• When we add nutrients, certain organisms can thrive at the

expense of other organisms

(eutrophication is an example of this)

• Biodiversity is the biological diversity in an ecosystem (how many different

types of living things exist in an environment) • Biodiversity allows for nutrients to be cycled

properly and allows the world to exist as we know it

• If we lose this biodiversity, the world as we know it will change

• Organisms are going extinct faster than normal right now

• Loss of biodiversity is a direct result of the negative impact humans have on the environment

Macromolecul e

Monomer (s)

Elements Functions Quick

Sketch

1.

2.

3.

Enzymes

• Enzymes are specific for:

– Temperature: work best at a specific temperature

– pH: work best at a specific pH

– Substrate: will only catalyze reactions with the right substrate

– Concentration: more enzyme = more reaction; more substrate = increased reactions until all the enzymes are “full”

• If enzymes are in the wrong temperature or pH, they will be inactive

• When molecules have charges, the molecules are polar molecules

• They have an unequal distribution of electrons

• Cohesive Behavior

– Cohesion

– Adhesion

• _{Surface Tension}

– Capillary Action

• Water as a solvent

• Expansion upon freezing

• _{Ability to moderate temperature}

 Properti

The cell theory states:

1. All living things are made of one or more cellsone or more cells.

1. Cells are the basic

structural and functional units of living things

 Cell

The cell theory states:

3. All cells come from other cells by

cell

cell divisiondivision.

 Cell

Cell Types

• There are 2 main types of cells: ProkaryotesProkaryotes and

Eukaryotes. They are

Eukaryotes. They are

both alive!

both alive!

 Types of

Cell Membrane Picture

Phospholipid

2-layer boundary between the

inside and outside of the cell

Transport Protein

transports materials into and out of the cell through the cell

Passive Transport

Passive transport is movement of movement of particles

particles across the cell membrane that does not require energy.not require energy

high concentration  low concentration (with concentration gradient)

(Concentration

(Concentration is the amount of something in a certain space)

The concentration gradient is the

difference in the amount of a substance in two different areas

Where would water go?

Solution

Effect

Isotonic: concentration is the same inside and outside the cell. Water moves in and out equally

Hypertonic: solution has a high

concentration of solutes than the cell. Water moves out of the cell

Hypotonic: Cell has a high concentration of solutes than

Active Transport

Active transport requires the cell to use energy

low concentration  high concentration.

The cell is working against the

concentration gradient.

 Active

Cytoskeleton

c

Plant vs. Animal Cells

• Both are Eukaryotic Cells • _{Plant Cells have}

– Chloroplasts

– Central Vacuole

– _{Cell Well}

Plant Organs

Plant Tissues

• Within the roots, stems, and leaves, there are specialized tissues

Plant

Structures

Stomata are holes in the leaves that allow for gas exchange

stomata is plural, stoma is singular

Plant

Structures

the roots to the rest of the plant.

-Phloem carries sugar from the leaves to the rest of the plant.

-Both roots and stems contain vascular tissues called xylem and

EQUATION FOR

PHOTOSYNTHESIS

6CO

+ 12 H

O + light

energy



C

H

O

+

EQUATION FOR PHOTOSYNTHE

SIS

•

_{Photosynthesis}

occurs in the

chloroplasts of plant

cells

•

_{Photosynthesis}

converts solar energy

to chemical energy

(stored in glucose)

•

_{Photosynthesis}

Factors Affecting Photosynthesi

s

• Water: water shortages can slow or stop photosynthesis

• Temperature: Enzymes for photosynthesis work best between 0 °C and 35°C

• Light Intensity: The more intense the light, the higher the rate of photosynthesis

– There is a maximum rate

Cellular

Cellular

Respiration

Equation for Cellular Respiration

Equation for Cellular Respiration

•

_{The overall process of respiration can}

_{The overall process of respiration can}

be summarized as:

be summarized as:

6 O

6 O₂₂ + C + C₆₆HH₁₂₁₂OO₆₆ → 6 CO → 6 CO₂₂ + 6 H + 6 H₂₂O + ATP O + ATP

Oxygen + glucose → carbon dioxide water (energy)

• _{2 Types of Anaerobic respiration:2 Types of Anaerobic respiration:} –Alcoholic Fermentation_{Alcoholic Fermentation}

• Pyruvates converted to alcohol_{Pyruvates converted to alcohol}

• Occurs in Yeast_{Occurs in Yeast}

• Glucose _Glucose  Alcohol + CO2 Alcohol + CO2 –Lactic Acid Fermentation_{Lactic Acid Fermentation}

• Pyruvates converted to lactic acid_{Pyruvates converted to lactic acid}

• Occurs in muscle cells_{Occurs in muscle cells}

• Glucose _Glucose  Lactic Acid+ CO2 Lactic Acid+ CO2

Comparing Photosynthesis and

Comparing Photosynthesis and

Respiration

• _{Step 1: Helicase and}

other enzymes unwind and unzip the DNA

double helix. and

•

_{Step 2: An}

RNA primer

binds to the

template

• _{Step 3: The enzyme} DNA polymerase

adds complementary DNA nucleotides to bond with the free nucleotides on the original DNA

• _{Step 4: Two double} stranded DNA

molecules that are

identical to each other and to the original

DNA

Only

RNA Only

Both

-Can leave the nucleus

-Uses ribose sugar

-Uses A, G, C -type of

•

_{Every 3}

nucleotides is a

codon. Each

•

_{Bottom loop of tRNA}

contains a 3 nucleotide

anticodon

.

•

_{When the tRNA anticodon}

binds to the mRNA

codon, the amino acid

• _{Genetic code is}

universal!

• The codon code for

the same amino acids in all organisms –

evolutionary evidence

• _{For every gene, there}

-any change in DNA sequence (order of nucleotides) is a mutation.

-mutations can be caused by mistakes in DNA replication, in transcription, in cell division and by other outside factors.

-Mutations result in genotypic change but may or may not result in phenotypic

change.

-A point mutation is a change in one base pair in a DNA sequence. A point

mutation causes the mRNA to change which can cause a change in the amino acid sequence, changing the structure of the protein

Example:

DNA RNA Amino Acid

TAC  AUG  Methionine TTC  AAG  Lysine

-Or a point mutation may not cause a change in the amino acid sequence because there are multiple codons for each amino acid:

DNA RNA Amino Acid

GGG  CCC Proline GGA  CCU Proline

Normal

Point mutation

mRNA

Protein _Stop

Stop mRNA

Protein

-Sickle cell anemia is a blood disease caused by a point mutation.

-A single nucleotide is changed from “A” to “T” which causes the amino acid to change from glutamic acid to valine:

Amino acids: Thr – Pro – Glu – Glu Normal: ACT CCT GAG GAG

-A frameshift mutation is when one nucleotide is added or deleted from the DNA strand.

-A frameshift mutation is much worse than a point mutation because it causes the entire DNA

sequence to be shifted over!

Example: DNA: ATTAAACCG

ATAAACCG

mRNA Protein

Frameshift mutation