The CellThe Cell

Anatomy and PhysiologyAnatomy and Physiology

Cell TheoryCell Theory

The Cell Theory States:The Cell Theory States: When Schleiden and Schwann When Schleiden and Schwann

proposed the cell theory in 1838, proposed the cell theory in 1838, cell biology research was forever cell biology research was forever changed. The cell theory states changed. The cell theory states that: that:

1.1. All life forms are made from one All life forms are made from one or more cells. or more cells.

2.2. Cells only arise from pre-existing Cells only arise from pre-existing cells. cells.

3.3. The cell is the smallest form of The cell is the smallest form of life. life.

the Generic Cell

Cell DifferentiationCell Differentiation

Cytoplasmic Organelles

•Cytoplasm: material between plasma membrane & nucleus.

•Organelle: “little organ” –Carry out specific functions. –Essential for normal cell function.

MitochondriaMitochondria

Ribosomes Composed mainly of

protein and RNA •They are the site for

protein synthesis. Some are located on

the outer membrane of the RER and some are free floating in the cytoplasm.

Rough Endoplasmic ReticulumRough Endoplasmic Reticulum

The RER can best The RER can best be described as a be described as a network of network of interconnected interconnected membranes that membranes that have ribosomes have ribosomes located on the located on the

Smooth Endoplasmic Reticulum

•Also called SER.•Contain NO Ribosomes.–Play no role in protein synthesis.•Serves the following functions:–Lipid Metabolism.–Synthesis of steroid-based hormones.–Absorption, synthesis, transport of fats.–Detoxification of drugs.–Breakdown of glycogen to glucose.

NucleusNucleus

Nucleoli –composed largely of Nucleoli –composed largely of protein and RNAprotein and RNA

Plasma Membrane

•Separates intracellular fluid within from extracellular fluid outside.

•Fluid Mosaic Model: –Double layer (Bi-layer) of lipid molecules. –Proteins float within the bi-layer. •Hydrophilic: –“Water-Loving”; charged polar head. •Hydrophobic: –“Water-Fearing”; uncharged non-polar tail.

Passive TransportPassive Transport - - requires no requires no energyenergy and moves with the and moves with the

concentration gradientconcentration gradient DiffusionDiffusion is the net movement of a substance (liquid or gas) is the net movement of a substance (liquid or gas)

from an area of higher concentration to one of lower from an area of higher concentration to one of lower concentration. The majority of the molecules move from higher concentration. The majority of the molecules move from higher to lower concentration, although there will be some that move to lower concentration, although there will be some that move from low to high. The overall (or net) movement is thus from from low to high. The overall (or net) movement is thus from high to low concentration. Eventually, if no energy is input into high to low concentration. Eventually, if no energy is input into the system the molecules will reach a state of equilibrium the system the molecules will reach a state of equilibrium where they will be distributed equally throughout the system.where they will be distributed equally throughout the system.

high concentration of dye equilibrium is reached high concentration of dye equilibrium is reached

OsmosisOsmosis is the diffusion of is the diffusion of waterwater across a semi- across a semi-permeable (or differentially permeable (or differentially permeable or selectively permeable or selectively permeable) membrane. permeable) membrane.

In general, water moves toward In general, water moves toward the area with a higher solute the area with a higher solute concentration because it has a concentration because it has a lower water concentration.lower water concentration.

Filtration and Facilitated Filtration and Facilitated Diffusion Diffusion Filtration is a passive Filtration is a passive

transport system that transport system that depends on hydrostatic depends on hydrostatic pressure.pressure.

Ex – Like a coffee filter Ex – Like a coffee filter

Facilitated DiffusionFacilitated Diffusion is a passive transport is a passive transport

system that goes with the system that goes with the concentration gradient but concentration gradient but moves large molecules moves large molecules through the protein through the protein channelschannels..

Great link for Passive and Great link for Passive and Active Transport SystemsActive Transport Systems

http://www.northland.cc.mn.us/http://www.northland.cc.mn.us/biology/Biology1111/animations/biology/Biology1111/animations/active1.swfactive1.swf

Active TransportActive TransportRequires the use of energy and goes Requires the use of energy and goes against the concentration gradientagainst the concentration gradient

Ex. Na K pumpEx. Na K pump Endocytosis Endocytosis

PINOCYTOSIS – cell PINOCYTOSIS – cell drinkingdrinking

PHAGOCYTOSIS- PHAGOCYTOSIS- cell eatingcell eating

Exocytosis Exocytosis

Cellular Cellular RespiratioRespiratio

nn GlycolysisGlycolysis

AnaerobicAnaerobic Takes place in Takes place in

cytosolcytosol 2 Atp2 Atp Produces 2 Produces 2

pyruvatespyruvates Kreb’s CycleKreb’s Cycle

AerobicAerobic Takes place in Takes place in

mitochondriamitochondria 2 ATP , 2 ATP ,

CO2,NADH,FADH2CO2,NADH,FADH2 Electron Transport Electron Transport

SystemSystem 32 ATP 32 ATP

Mitosis StagesMitosis StagesProphaseProphase

Metaphase Metaphase Anaphase and TelophaseAnaphase and Telophase

MeiosisMeiosis MeiosisMeiosis

Meiosis is divided into two parts: meiosis I and meiosis II. At Meiosis is divided into two parts: meiosis I and meiosis II. At the end of the meiotic process, there are four daughter cells the end of the meiotic process, there are four daughter cells rather than the two produced at the end of the mitotic process. rather than the two produced at the end of the mitotic process. Each of the resulting daughter cells has one half of the number Each of the resulting daughter cells has one half of the number of chromosomes as the parent cell. of chromosomes as the parent cell.

Image credit: Copyright S.L. Forsburg 2000. Used with permission. AllImage credit: Copyright S.L. Forsburg 2000. Used with permission. All

Nucleic AcidsNucleic Acids

DNA – genetic codeDNA – genetic code Double Stranded Double Stranded Contains base pairsContains base pairs

A-T and C-GA-T and C-G Sugar = Sugar =

deoxyribosedeoxyribose

RNA – protein RNA – protein synthesissynthesis Single strandedSingle stranded Contains base pairs Contains base pairs

A-U and C-GA-U and C-G Sugar = riboseSugar = ribose

ReplicationReplication When body cells divide and When body cells divide and

DNA replicates – during DNA replicates – during InterphaseInterphase

TranscriptionTranscription To make proteins - the To make proteins - the

code is read from a specific code is read from a specific area on the DNA and area on the DNA and copied to mRNAcopied to mRNA

TranslationTranslation The code from mRNA is The code from mRNA is

read on the ribosome and read on the ribosome and translated to the have the translated to the have the tRNA bring the correct tRNA bring the correct amino acid for making the amino acid for making the protein.protein.

Replication and Replication and Protein SynthesisProtein Synthesis

DNA is transcribed into mRNA which is translated into amino acids.

This is