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Honors Fall Final Review

What is a theory? A theory is a hypothesis that has been confirmed

many times.

What is the scientific method?The scientific method has several steps:

ObservationHypothesisExperimentationData CollectionConclusionRetest

Identify the Independent and dependent variables

In graphs, the independent variable is on the X-axis.The dependent variable is on the Y-axis.

0

2

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14

0 10 20 30 40 50

Met

abo

kic

rate

(arb

itar

y u

nit

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Temperature (degree celcus)

Metabolic rate of a rat at different temperatures

Independent Variable

Dep

ende

nt

Var

iabl

e

Analyze the data An ichthyologist was recently

visiting a friend in Nord, Greenland and noticed that the breathing rate of a certain fish was much slower than the same type of fish she had studied in her hometown of Miami, Florida. She believed that this difference was caused by the colder water temperatures in Nord. The scientist decided to experiment with fish in tanks and collect some data to determine if her ideas were supported or not. Below is the data she recorded during her experiment.Based on the data, what should the

scientist conclude?As the temperature gets hotter,

breathing rate speeds up…to a point. After 23⁰ the breathing rate slows down again.

Identify the variables A scientist observed that white mice that were fed seeds with

high protein appeared to grow more than mice given leafy and yellow vegetables. The scientist hypothesized that the protein in the seed was responsible for the growth. He designed an experiment to test this hypothesis. He divided 200 mice of the same age, size, health, and sex into two groups of 100 mice each. The mice were kept under identical conditions for 14 days. One group was given a diet of seeds. The other group was given a diet of leafy and yellow vegetables. The mass of each mouse was recorded daily for 14 days.What is the dependent variable?

The dependent variable is the amount of growth.What is the independent variable?

The independent variable is the type of food—seeds with high protein.

What are some controls in this experiment?The mice given the leafy and yellow vegetables.

What are some constants in this experiment?100 mice in each group, same age, size, health, and sex. Getting

mass of both in 14 days.

Make an experiment.Smithers thinks that a special

juice will increase the productivity of workers. How would you design an

experiment from this observation?Hypothesis

If workers have juice, then they will be more productive.

ExperimentMake 2 groups of workers, one gets

the juice, the other does not. Have them perform the same task—i.e. like stapling papers. Measure how many papers are stapled after a period of time.

What should you conclude?After the experiment,

Smither’s finds that the group that got the special juice stapled 1,123 papers, and the group that did NOT receive the special juice stapled 4,323 papers.What should you conclude?

That the special juice does not improve productivity.

What is the next step?Do the experiment again!

Repeat to prove results.

What is pure and applied science?

Pure ScienceAnswers questions about

phenomena and mechanisms in the natural world.

Why do you do it?Because we wanted to know!

EX. Studying the ICE MAN

Applied ScienceApplication of scientific

knowledge to practical problems.Why do you do it?

To fight disease, identify criminals, learn how to store hazardous wastes…etc.

Organization of Life Atoms Molecules Compounds Cells Tissues Organs Organ

systems Organisms Species Population Community Ecosystems Biosphere

What is the cell theory?

1. All organisms are made of cells.

2. Cells are the basic unit of structure and function in living things.

3. All cells come from pre-existing cells.

Similarities and differences between Prokaryote and eukaryote cells.

ProkaryoteEukaryote

1. Living

2. Cytoplasm

3. DNA

4. Cell Membrane

5. Ribosomes

6. Can be unicellular

1. Membrane-bound organelles

2. DNA in nucleus

3. Larger and Multicellular or unicellular

5. Ex: Plants, Animals, Protists and Fungi

BOTH

1. No membrane bound organelles

2. free-floating DNA

3. Smaller and only unicellular

4. Ex: Bacteria

What does organic and inorganic mean?

Organic A compound that

contains carbonUsually pertains to

anything living Inorganic

Typically either does not contain significant amounts of carbon, or is non-living.

What are the four main carbon-based molecules (macromolecules) and their roles?A. Carbohydrates

Used for quick energyB. Proteins

Used for structures like hair, skin, organs, muscles etc.

C. LipidsUsed for long-term energy storage

D. Nucleic AcidsUsed to store genetic information

What are macromolecules?They are POLYmers

made of many smaller units called MONOmersCarbohydrates – used for quick

energyLipids – used for long term

energy and cellular structures like the cell membrane

Proteins – used to build many structures, enzymes, neurotransmitters, and hormones.

Nucleic Acids – carry genetic information (DNA and RNA)

They are ORGANICThat means they all have

CARBON!

What are some energy storing molecules?Plants use

STARCHAnimals use

GLYCOGEN and TRIGLYCERIDESSugar and fat

What are the characteristics of enzymes?

1. They are PROTEINS!

2. They SPEED UP the RATE of chemical reactions by LOWERING ACTIVATION ENERGY

3. They are REUSABLE. They can be used over and over again.

4. They are SPECIFIC. An enzyme only works on very specific substrates

* They attach to the substrate, change their shape, causing a chemical reaction, and when released, they can be reused.

What are the cells organelles and their functions?

Cell wallIn plants onlyCell walls are carbohydrate

frameworks (cellulose) for mechanical support

Cell membraneLipid bi-layer membrane that forms a

boundary between the inside and outside of the cell.Regulates what comes into and out of the

cell.

LysosomeIs the “stomach” of the cell, breaks

down moleculesProgrammed for cell death

What are the cells organelles and their functions?

MitochondriaPowerhouse of the cellCreates ATP

Golgi ApparatusPackages and modifies proteins

for exportSmooth Endoplasmic Reticulum

Makes lipids, detoxifies the cell, and involved in cell metabolism.

Rough Endoplasmic ReticulumCreates proteins for use by the

body and cell.

What are the cells organelles and their functions?

NucleusControl center of the cell, contains DNA

Nucleolus = where ribosomes are made

RibosomesAssist in the assembly of proteinsInvolved in DNA translation and

transcriptionChloroplasts

In plants only, specialized for photosynthesis.

What organelle is responsible for exocytosis?The golgi apparatus exports

vesicles from the cell!

Why are the mitochondrion and golgi apparatus folded?The mitochondiron

and golgi apparatus are folded to create more surface area! More surface area

means more area to do work.Like your intestines.

What is another name for the plasma membrane?

The plasma membrane is also known as a fluid mosaic.Fluid = the lipids

that fluidly slide past each other

Mosaic = the proteins that are throughout the membrane

What are centrioles? Are they in plant or animal cells or both?Centrioles are

located in animal cells only, and they help anchor the spindle fibers during mitosis and meiosis.

What is the function of water in a cell?Water helps a cell

maintain its shape!Plant cells will wilt

without water.

Compare Plant and Animal Cells

What is a tissue?A tissue is a bunch

of cells doing the same job.Like skin tissue!Like heart tissue!

Real size of a blue whale heart.

Arrange these in order… Atom Cell Tissue Organ Organ

System Organism

Scientists who determined the structure and function of DNAGriffiths: worked with

pneumonia bacteria – came up with idea that something was a transforming principleAvery: furthered

Griffiths work – said DNA was “transforming principle”

Doc, I think I have pneumonia!

The transforming principle is DNA!

Hershey and Chase: Worked with bacteriophages and confirmed DNA was genetic material.

Wilkins and Franklin: took x-ray diffraction images of DNA

Scientists who determined the structure and function of DNA

I’ll insert my DNA into this bacteria and take it over!

Watson and Crick: built DNA double helix model

Chargaff: discovered base pairing rules (A to T and C to G)

Scientists who determined the structure and function of DNA

What is the function of DNA?

Stores genetic informationContains instructions for making PROTEINS

What are the components of DNA?

DNA is a polymer made of nucleotides.

The nucleotides have a phosphate, sugar, and nitrogenous base.There are four different types of

nitrogenous bases.Adenine ThymineCytosineGuanine

How do you get from DNA to chromosomes to genes?

DNA has ALL genetic information

DNA is coiled into chromosomes during replication

Chromosomes contain genes that will become traits

What is the difference between DNA and RNA?DNA RNA

Purpose

Structure

Sugar

Bases

Carries genetic information

Assists in “reading” the information on

DNA

Double stranded Single stranded

Deoxyribose Ribose

Adenine

Guanine

Cytosine

Thymine

Adenine

Guanine

Cytosine

Uracil

Location Nucleus Nucleus and cytoplasm

The Cell CycleG1

Cell growsDuring G0, the cell does

its job and either never or rarely divides

SCell replicates its DNA

G2

Cell grows againALL of these are

INTERPHASE!

What makes the cell move from phase to phase in the cell cycle?There are checkpoints within the cell cycle

that are controlled by enzymes and hormones. If the cell is not ready to move on the

enzymes will prevent then next phase from happening.

If the cell IS ready then other enzymes allow the cell to proceed.

What are the purposes and processes of Mitosis?Division of the nucleus

Used for repair and growthOnly happens in EUKARYOTIC

cellsIncludes 4 steps

ProphaseMetaphaseAnaphaseTelophase

Results in:TWO genetically IDENTICAL

DIPLOID daughter cells

What are the purposes and processes of Meiosis?Produces gametes (egg or

sperm)Includes 8 steps

Prophase IMetaphase IAnaphase ITelophase IProphase IIMetaphase IIAnaphase IITelophase II

Results in:4 genetically DIFFERENT HAPLOID

daughter cells.

What is crossing-over?

Sister chromatids in a tetrad cross over each other Pieces of

chromosomes or genes are exchanged Produces

genetic recombination in the offspring

These are called homologous chromosomes

What is the difference between mitosis and meiosis?

What is the difference between mitosis and meiosis?

Mitosis Meiosis

# of divisions

# of daughter cells

Genetically Identical

Chromosome #

Where

When

Role

1

2

Yes

46 (diploid)

Somatic (body) cells

Throughout life

Growth and repair

2

4

No

23 (haploid)

Gamete cells

After puberty

Sexual reproduction

What does haploid and diploid mean?

DiploidDi = twoPloid = chromosomes

Having two chromosomes for each trait

In humans 46 (normal body cells)

HaploidHap = half or onePloid = chromosomes

Having one chromosome for each traitIn humans 23 (gamete; egg or sperm)

What occurs on the cellular level during fertilization?

Father contributes 23 chromosomes

Mother contributes 23 chromosomes

Fertillization results in a recombined 46 chromosomes

What is photosynthesis?

A process to capture energy from sunlight to make sugars.Takes place in the CHLOROPLASTSUses the light capturing molecule

chlorophyllIncludes the Light-Dependent Reaction

Sunlight hits the chlorophyll and generates energy which is trapped in NADPH and ATP

Includes the Light-Independent (dark) ReactionCalvin Cycle: NADPH and ATP used to make

glucose6CO2 + 6H2O C6H12O6 + 6O2 Carbon Dioxide + Water Glucose + Oxygen Energy carrying molecules are: NADPH and ATP

Why do leaves appear to be green?Sunlight

containing all colors hits the chlorophyll in the chloroplast. The red and violet light are absorbed while the green light is reflected making the leaf appear green.

What is cellular respiration?Releases chemical energy from

sugars and other carbon based molecules to make ATPTakes place in the MITOCHONDRIABoth PLANTS & ANIMALS undergo

cellular respiration which includes Glycolysis- breaks down glucose into 2

pyruvateKrebs Cycle- breaks down Acetyl (at this

point all C from glucose is now CO2)Electron Transport Chain- 32 ATP are

produced, oxygen bonds with H to form H2O

C6H12O6 + 6O2 6CO2 + 6H2O

Glucose + Oxygen Carbon Dioxide + Water

Energy carrying molecules are : NADH, FADH2, and ATP

In cellular respiration, what molecules carry available energy?All energy is neither created or destroyed it

is merely transferred from one source to another.

ENERGY STORAGE

ENERGY STORAGE

What does anaerobic and aerobic mean?

AnaerobicAn = notAerob = uses oxygen

Processes or organisms that do not require oxygenEx. Glycolysis and fermentationSome bacteria are anaerobic and do not require

oxygen

AerobicAerob = uses oxygen

Processes or organisms that do require oxygenEx. Cellular RespirationMost bacteria are aerobic and do require oxygen

What are the differences between photosynthesis and cellular respiration?

Photosynthesis Cellular RespirationOrganelle for

ProcessReactants

Electron Transport Chain

Cycle of Chemical Reactions

Products

Chloroplast

CO2 and H2O

Makes ATP and NADPH to make sugar

Calvin Cycle builds the sugar molecule (C6H12O6)

Sugar (C6H12O6) and O2

Mitochondria

Sugar (C6H12O6) and O2

Makes ATP to be used by the cells

Glycolysis breaks down the sugar molecule (C6H12O6)

CO2 and H2O

What is the relationship between the CO2 cycle and the O2 cycle?

Plant, animals, and most other organisms need oxygen for cellular respiration.Plants release oxygen

during photosynthesis. In turn, humans and other

organisms take in the oxygen and release it as carbon dioxide through respiration. Plants then take in the

carbon dioxide, utilize it as part of photosynthesis, and release oxygen as a waste product.

What happens during fermentation?• Fermentation is an anaerobic process

that takes place when there is less oxygen in the body (i.e. during strenuous activity or when fruit falls off the plant.)

• Fermentation does make 2 ATP, and it allows glycolysis to continue.

• Plants and yeast undergo alcoholic fermentation.

• Animals undergo lactic acid fermentation.

What are some mechanisms of cellular transport?Passive Transport

Simple diffusionFacilitated diffusion

Does not require energy.Molecules move DOWN the

concentration gradient from high to low concentration.People getting off a crowded train!

Active TransportRequires Energy (ATP)

Molecules are pushed AGAINST the concentration gradient from low to high concentration.Think about the people getting

pushed onto a crowded train!

What are types of transport proteins?

Channel proteins are embedded in the cell membrane & have a pore for materials to cross

Carrier proteins can change shape to move material from one side of the membrane to the otherVesicles are formed by

both the cell membrane and the golgi apparatus to assist molecules across the membrane.

What is diffusion?Passive Transport

Requires NO ENERGYSimple diffusion

Down a concentration gradientSolutes automatically diffuse from HIGH to

LOW concentrationFacilitated diffusion

Down a concentration gradientSolutes diffuse from HIGH to LOW

concentration Solutes USE A PROTEIN to help them cross the

lipid bi-layer

What is osmosis?

The diffusion of water across a semi-permeable membraneIs passive diffusionRequires NO energyWater will go from an area

of LOW solute concentration to HIGH solute concentration

Diffusion occurs until they reach equilibrium- there is no concentration gradient.Think of a tea bag in water

Draw a picture representing osmosis?

What are the special properties of water?

Water is POLARThe molecule has a positive and negative side.Oxygen is an electron hog, and will be slightly negative.Allows 2 molecules to form HYDROGEN BONDS

Water is a UNIVERSAL SOLVENTWith time, water can dissolve almost any substance.

Water has CAPILLARY ACTIONIt can move up a narrow tube AGAINST the force of gravity

Water has ADHESION and COHESIONAdhesion – water and other substance (like glass) cling

togetherCohesion – water and water cling together

Water is LESS DENSE as a solid (when compared to liquid formIce floats on water

What are isotonic, hypotonic, and hypertonic solutions?

IsotonicSolute

concentration is the same inside and outside the cell.

Water moves equally into and out of the cell.Normal Cell

What are isotonic, hypotonic, and hypertonic solutions?Hypotonic

Solute concentration outside the cell is LOWER than solute concentration inside the cell.

Water is moving INSIDE the cellCell swells and burst

cytolysis

What are isotonic, hypotonic, and hypertonic solutions?Hypertonic

Solute concentration outside the cell is HIGHER than solute concentration inside the cell.

Water is moving OUTSIDE the cell.Cell shrinks

plasmolysis

What is active transport? How is it different from passive transport?In active transport

particles/molecules move from low concentration to high concentration; energy is required.Passive transport is when

particles/molecules move from high to low concentration; no energy is required.