Exam Review Day 2• Active Transport- movement across the

cell membrane that requires energy ATP• Passive Transport- movement across the

cell membrane using a protein channel• Diffusion- movement from high to low

concentration. Across a concentration gradient

• Osmosis- diffusion of water• Semipermeable membranes- cell

membranes that controls the passage of materials in and out of cell

Cell Membrane

The Cell Membrane regulates what enters and leaves the cell. It also provides protection and suport.

It is often described as the “fluid mosaic model”

Composed of a Lipid Bilayer. Oxygen and Carbon Dioxide pass through this layer.

Protein Channels allow large molecules to move across the membrane

library.thinkquest.org/.../cell_membrane.gif

Diffusion

• Molecules are in constant motion• Diffusion is the movement of molecules from an

area of high concentration to low concentration.• Diffusion does not require the cell to use energy.

• Diffusion• Diffusion

Osmosis• Osmosis is the diffusion of water through a selectively

permeable membrane. This does not require energy.

Active Transport• Active transport is the movement of molecules against the

concentration ( from areas of low concentration to high concentration).

• This requires energy from the cell.

What Are Enzymes?What Are Enzymes?•All enzymes are Proteins Proteins butbut

NOTNOT all proteins areall proteins are enzymesenzymes

•Act as CatalystCatalyst to speed up

chemical reactions

•Not permanentlyNot permanently changed in the process (reusable)

Parts of an Enzyme Reaction• The Enzyme provides a site for the reaction to

occur. Active Site• The reactants, or compounds to be broken or put

together, are called the Substrate.• The combination of the enzyme and the substrate

during the chemical reaction is called the Enzyme-Substrate Complex

Enzymes

• enzyme

Cellular RespirationGlucose + oxygen -> yields -> carbon dioxide +

water and ATP

• A glucose molecule is broken down into useable energy, in the form of ATP.

• The mitochondria is the site of aerobic cellular respiration

• The cytoplasm of a cell is the site of anerobic respiration

Cellular Respiration- Anaerobic

• Anaerobic- Without oxygen. Takes place in the cytoplasm of the cell.

• Yeast- alcohol fermentation- alcohol, carbon dioxide and 2 ATP molecules.

• Bacteria and muscles- lactic acid and 2 ATP molecules

• Anaerobic respiration uses 1 glucose molecule and makes only 2 ATP molecules.

Cellular Respiration- Aerobic

• Aerobic respiration takes place in the mitochondria of the cell.

• From one glucose molecule the mitochondria makes 36 ATP molecules of energy and releases carbon dioxide and water. This is the most efficient use of the glucose molecule. The ATP molecules are used by the cell for work.

PhotosynthesisEnergy from the sun +water + carbon dioxide glucose + oxygen +

water

• Light energy comes from the sun and is the original source of all energy on the planet.

• Plants take in carbon dioxide from the atmosphere

• Water is taken in by the roots and travels to the leaf and finally the chloroplasts.

Photosynthesis• Light Intensity affects

photosynthesis.• The more light- more

photosynthesis takes place

• Light Color• Plants use blue and red

light for photosynthesis• Amounts of CO2 present

controls the rate of photosynthesis

Photosynthesis

• Plants use wavelengths of light to photosynthesis.

• Blue and Red wavelengths are used by plants.

• Green light, 550 nm on the spectrum is not used

Photosynthesis

• Plants use the glucose they produced for energy during cellular respiration.

• Plants store the glucose in large macromolecules for later energy use- Starch.

• Plants use the glucose to make macromolecules of cellulose for structure.

Carbon Cycle

The products of photosynthesis are the reactants for cellular respiration.

Energy is converted to chemical energy- glucose, in photosynthesis. Cellular respiration converts the energy in glucose into ATP molecules of energy

Plants store the carbon in the glucose molecule.

Carbon dioxide is in the atmosphere.

DNA- double helix

Protein Synthesis

• Transcription- DNA copied to mRNA. This occurs in the nucleus.

• A-U C-G

• Translation- mRNA goes to the ribosomes and is translated into proteins. tRNA brings the amino acids to the ribosome to be made into proteins.

• DNA to m

DNA- tacaatgcgact

Mitosis

• Mitosis – The division of a cell nucleus to make two identical daughter cells.

• There are 4 divisions of Mitosis.

• Prophase• Metaphase• Anaphase• Telophase • And finally Cytokinesis, where

the cell separates into two new identical cells.

MeiosisMeiosis• Similar in many ways to mitosisSimilar in many ways to mitosis• Several differences howeverSeveral differences however

– Involves 2 cell divisionsInvolves 2 cell divisions– Results in 4 cells with 1/2 the normal genetic information.Results in 4 cells with 1/2 the normal genetic information.

• Vocabulary:Vocabulary:– Diploid (2N)Diploid (2N) - Normal amount of genetic material - Normal amount of genetic material– Haploid (N)Haploid (N) - 1/2 the genetic material. - 1/2 the genetic material.

• Meiosis results in the formation of haploid cells.Meiosis results in the formation of haploid cells.– In Humans, these are the In Humans, these are the OvaOva (egg) and (egg) and spermsperm..

• Meiosis occurs in 2 phases: Meiosis occurs in 2 phases: Meiosis 1Meiosis 1 & & Meiosis 2Meiosis 2

Overview of MeiosisOverview of Meiosismeiosis animation

Crossing OverCrossing Over• Segments of Segments of

homologous homologous chromosomes break chromosomes break and reform at similar and reform at similar locations.locations.

• Results in new Results in new genetic genetic combinations of combinations of offspring.offspring.

• This is the main This is the main advantage of sexual advantage of sexual reproductionreproduction

MitosisMitosis MeiosisMeiosisNumber of Number of

divisionsdivisions 1122

Number of Number of daughter cellsdaughter cells 22 44

Genetically Genetically identical?identical? YesYes NoNo

Chromosome #Chromosome # Same as parentSame as parent Half of parentHalf of parent

WhereWhere Somatic or Body Somatic or Body cellscells

Germ cells- or Sex Germ cells- or Sex Cells Cells

WhenWhen Throughout lifeThroughout life At sexual maturityAt sexual maturity

RoleRole Growth and repairGrowth and repair Sexual reproductionSexual reproduction

Comparison of DivisionsComparison of Divisions

Definitions Definitions AllelesAlleles - - two forms of a two forms of a gene gene (dominant & (dominant &

recessive)recessive) DominantDominant - - stronger of two genes expressed in the stronger of two genes expressed in the

hybrid; represented byhybrid; represented by aa capital letter (R)capital letter (R) RecessiveRecessive - - gene that shows up less often in a gene that shows up less often in a

cross; represented by across; represented by a lowercase letter (r)lowercase letter (r) PhenotypePhenotype - - the physical feature resulting from a the physical feature resulting from a

genotypegenotype (e.g. red, white) (e.g. red, white) GenotypeGenotype - - gene combination for a traitgene combination for a trait (e.g. RR, Rr, (e.g. RR, Rr,

rr) rr) Homozygous RR rrHomozygous RR rr Heterozygous RrHeterozygous Rr

• Trait: Tall vs short plantsTrait: Tall vs short plants• Alleles: Alleles: T- tallT- tall t-shortt-short• Cross: Cross: Tall plantsTall plants xx Tall PlantsTall Plants• TtTt xx Tt Tt

Monohybrid CrossMonohybrid Cross

T

t

tT

TT

ttTt

Tt

Genotype:Genotype: TT, Tt, TT, Tt, tttt

PhenotypePhenotype: Tall Tall and shortand short

G.Ratio:G.Ratio: 1:2:11:2:1

P.Ratio:P.Ratio: 3:1 3:1

Questions 49-52 omit 53

• 49. Mr. Jones could have AA or AO Blood.• 50.• 51.

• 52. More than one gene controls the trait. Ex. Height and skin color in humans.

DNA electrophoresis

Recombinant DNA

• Used to produce human insulin using bacteria