2nd Lec - The Cell

7/31/2019 2nd Lec - The Cell

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The Cell and theThe Cell and the

BiomoleculesBiomolecules


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Why do we need to review theWhy do we need to review the

cell structure?cell structure?

In biochemistry, we are going to study theIn biochemistry, we are going to study the

biomolecules that make up thebiomolecules that make up the

components of the cell.components of the cell.

The biochemical reactions that we willThe biochemical reactions that we will

study take place in these cellularstudy take place in these cellularcomponents.components.


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The CellThe Cell

is the simplest unit of living things

Types of Cells

1. Prokaryotic cell

-Eubacteria, Archaebacteria

2. Eukaryotic cell

-fungi, plants and animals


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Prokaryotic CellProkaryotic Cell

lacks a nucleus

(DNA is packed in anucleoid region of

the cytoplasm)

no membrane-

bound

organelles.


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Eukaryotic CellEukaryotic Cell

has membrane-boundhas membrane-bound

nucleus containing thenucleus containing the

chromosomeschromosomes

with membrane-enclosedwith membrane-enclosed

distinct organelledistinct organelle

~1000-fold bigger than~1000-fold bigger than

prokaryotic cellsprokaryotic cells


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AnAnim

alCell

AnAnim

alCell


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APlantCell

APla

ntCell


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Eukaryotic cell:Eukaryotic cell: CompartmentalizationCompartmentalization

Advantage of having

membrane-enclosed

compartments: -separate

incompatible

chemical and

physical conditions
http://ntri.tamuk.edu/cell/mitochondrion.html


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Parts of the CellParts of the Cell

CytosolCytosol

NucleusNucleus

Endoplasmic reticulumEndoplasmic reticulum

Golgi complexGolgi complex MitochondrionMitochondrion

LysosomeLysosome

PeroxysomePeroxysome Cell wallCell wall

ChloroplastChloroplast

VacuolesVacuoles


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Cytoplasm & CytosolCytoplasm & Cytosol

Cytoplasm containsCytoplasm contains

the cell contentthe cell content(proteins& organelles).(proteins& organelles).

Cytosol is the waterCytosol is the water

solution (salts andsolution (salts and

organic molecules)organic molecules)

where organelles arewhere organelles are

suspended.suspended.
http://www.biols.susx.ac.uk/home/Julian_Thorpe/tem2.htm


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Prepping Cell Components forPrepping Cell Components for

AnalysisAnalysis


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Separation

by

Separationby

Centrifuga

tion

Centrifuga

tion


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Cell NucleusCell Nucleus

DN

A

containscontains

geneticgenetic

materialmaterial

site of DNAsite of DNA

and RNAand RNA

synthesissynthesis


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Endoplasmic Reticulum (ER)Endoplasmic Reticulum (ER)

network of membranesheets and tubules

extending from the

nucleus

protein processing and

transport

contains enzymes thatdetoxifies substances

Rough ER- contains ribosomes

Smooth ER lipid synthesis


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RibosomeRibosome

-facilitate-facilitateof proteinof protein

synthesissynthesis


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Golgi ApparatusGolgi Apparatus

membranousmembranous

vesicles stackedvesicles stacked

upon one anotherupon one another

sorts andsorts and

transportstransports

molecules (e.g.molecules (e.g.protein) for exportprotein) for export

to other cell parts.to other cell parts.


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MitochondriaMitochondria

site of cellularsite of cellular

respirationrespiration powerhouse ofpowerhouse of

the cellthe cell


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Lysosom

e

containscontains

hydrolytichydrolytic

enzymesenzymes

intracellularintracellular

digestiondigestion


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Peroxisome

contains oxidative

enzymes

intracellular

digestion


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VacuoleVacuole

nutrient, ionnutrient, ion

and waterand water

reservoirreservoir


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ChloroplastChloroplast

Thylakoids are membrane-bound organelles found

inside of a membrane-

bound organelle (the

chloroplast)


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The Cell and

its organelles

Examples of SupramolecularStructures

chromosome

cell membrane

cell wall

BiomoleculesBiomolecules

Nucleic acids

Proteins

Lipids

Carbohydrates

BIOMOLECULESBIOMOLECULES


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BIOCHEMICAL

SUBSTANCE

Non-carbon

containing

substances

Carbon containing

substances(bioorganic)

Water

(~70%)

Ions, small

molcules

(4%)

Proteins

(15%)

Lipids

(~2)

Carbohydrates

(2%)

Nucleic acids

(7%)



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Only 27 of the 90 elementsOnly 27 of the 90 elements

found in the earths crust arefound in the earths crust are

found in living things.found in living things.



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Most important elements in theMost important elements in the

biomoleculesbiomolecules

CarbonCarbon

HydrogenHydrogen

OxygenOxygen NitrogenNitrogen

PhosphorusPhosphorus

SulfurSulfur

Readily form covalent

compounds


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Common functional groups inCommon functional groups in


HydroxylHydroxyl

AcylAcyl

CarbonylCarbonyl CarboxylatesCarboxylates

Amino groups/aminesAmino groups/amines

SulfhydrylSulfhydryl Phosphoryl groups/phosphatePhosphoryl groups/phosphate


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Common functional groups inCommon functional groups in



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Linkages in biochemicalLinkages in biochemical

compoundscompounds

AmideAmide

EsterEster

EtherEther Phosphate esterPhosphate ester

PhosphoanhydridesPhosphoanhydrides


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Linkages in biochemicalLinkages in biochemical

compoundscompounds

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2nd Lec - The Cell