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UNDERSTANDINGSTRUCTURE AND
FUNCTION
It appears that life first emerged at least 3.8 billion years ago, approximately 750 million years after Earth was
formed
Simple Biological Molecules Were Formed Under Prebiotic Simple Biological Molecules Were Formed Under Prebiotic ConditionsConditions
• During the first billion years on earth, During the first billion years on earth, there was little free Othere was little free O22 and no O and no O33 to to absorb UV radiation from the sun. Simple absorb UV radiation from the sun. Simple organic molecules were formed under organic molecules were formed under such conditions.such conditions.
• Laboratory experiments simulating the Laboratory experiments simulating the primitive earth have confirmed that primitive earth have confirmed that organic molecules could have been organic molecules could have been formed formed
• When gases such as When gases such as COCO22, CH, CH44, NH, NH33, and H, and H22 were heated with water and energized by were heated with water and energized by electrical discharge or by UV radiation, electrical discharge or by UV radiation, they reacted and formed small organic they reacted and formed small organic molecules. molecules.
• More importantly, the organic molecules More importantly, the organic molecules (amino acids, nucleotides, sugars, and (amino acids, nucleotides, sugars, and fatty acids) were also generated. fatty acids) were also generated.
• Next step in evolution was the formation Next step in evolution was the formation of macromolecules through spontaneous of macromolecules through spontaneous polymerization and capable of polymerization and capable of reproduction and further evolutionreproduction and further evolution
• Stanley Miller’s experiment in 1950Stanley Miller’s experiment in 1950
Cells in culture, stained for keratin (red) and DNA (green).
What is Cell?What is Cell?Cell is the structural and Cell is the structural and functional unit of living functional unit of living
organisms.organisms.
What is cellWhat is cell
•Cell is the basic unit of Cell is the basic unit of organization of all living matter.organization of all living matter.
•Within a selective and retentive Within a selective and retentive semipermeable membrane, it semipermeable membrane, it contains a complete set of different contains a complete set of different kinds of units necessary for own kinds of units necessary for own growth and reproduction from growth and reproduction from simple nutrientssimple nutrients
• Every organism consists of cells; Every organism consists of cells; from the simplest single organism -the from the simplest single organism -the
bacterium to the most complex bacterium to the most complex multicellular organism.multicellular organism.
• Basic Properties of Cells Basic Properties of Cells – Cells are highly complex and Cells are highly complex and
organized.organized.– Cells possess a genetic program Cells possess a genetic program – Cells are capable of reproducing.Cells are capable of reproducing.– Cells acquire and utilize energy.Cells acquire and utilize energy.– Cells engage in numerous mechanical Cells engage in numerous mechanical
activities.activities.– Cells are able to respond to stimuli.Cells are able to respond to stimuli.– Cells are capable of self-regulation.Cells are capable of self-regulation.
Eukaryotes have a nucleus and many other organelles with
specialized function
• Living cells are divided into Living cells are divided into types based on internal types based on internal complexity.complexity.
TYPES OF CELLSTYPES OF CELLS
Prokaryotic Eukaryotic
1. no nuclear envelope
2. little noncoding DNA
3. no chromatin
4. ribosome subunits 70S
5. lack of cellular organelles
6. single circular chromosome
7. peptidoglycan cell wall
1. nuclear envelope
2. great deal of noncoding DNA
3. chromatin & remodelers
4. ribosome subunits 80S
5. cellular organelles
6. multiple linear chromosomes
7. no peptidoglycan
Prokaryotes Eukaryotes
The Cell Membrane The Cell Membrane •The cell membrane The cell membrane functions as a semi-functions as a semi-permeable barrier, permeable barrier, allowing a very few allowing a very few molecules across it. molecules across it.
•Consists mainly of Consists mainly of lipid bilayer with lipid bilayer with associated protein.associated protein.
• Ref:Ref:Basic Concept of Cell Basic Concept of Cell Biology and Histology Biology and Histology
• Author: McKenzieAuthor: McKenzie
• The cell membrane is about 7.5 nm thickThe cell membrane is about 7.5 nm thick
MEMBRANE STRUCTURE MEMBRANE STRUCTURE – Lipids + Proteins + Carbohydrates Lipids + Proteins + Carbohydrates
moleculesmolecules
FUNCTIONSFUNCTIONS • To control selective entrance and exit of To control selective entrance and exit of
materials. This allows the cell to materials. This allows the cell to maintain constant internal environment maintain constant internal environment
• Transport of small molecules like, water, Transport of small molecules like, water, OO22, CO, CO22 across the plasma membrane across the plasma membrane
The lipid bilayer is freely permeable to small, lipid soluble, nonpolar molecule but is impermeable to charged ions.
Molecular structure: The lipid bilayer is composed of phospholipid, glycolipid and chclesterol. Phospholipids are amphipathic, consisting of one polar (hydrophilic) head and two nonpolar (hydrophobic) fatty acid tail.
The polar head of each molecule face the membrane surface, whereas the tails project into the interior of the membrane.
The tails of the two leaflets face each other, forming weak bond that attach the leaflets to each other.
Glycolipids are restricted to the outer leaflets. Polar carbohydrate residues of glycolipids extend from the outer leaflet into the extracellular space and form part of the glycocalyx.
Cholesterol constitutes 2% of lipids helps maintain the structural integrity of the membrane.
The Cell Membrane The Cell Membrane
• Integral proteinsIntegral proteins
Span the entire plasma Span the entire plasma membrane and function as membrane and function as membrane receptor & membrane receptor & transport proteins. known transport proteins. known as gateway proteins.as gateway proteins.
• CARBOHYDRATESCARBOHYDRATES – Always located external to cellAlways located external to cell – Linked to proteins as glycoproteins; Linked to proteins as glycoproteins;
and to lipids as glycolipidsand to lipids as glycolipids
The Cell Membrane The Cell Membrane • Cholesterol is Cholesterol is
another important another important component of cell component of cell membranes membranes embedded in the embedded in the hydrophobic hydrophobic areas of the inner areas of the inner (tail-tail) region. (tail-tail) region.
• Most bacterial cell Most bacterial cell membranes do membranes do not contain not contain cholesterolcholesterol
The Cell MembraneThe Cell Membrane
• Cell membranesCell membranes– The membrane allows materials needed The membrane allows materials needed
for life processes to pass through and for life processes to pass through and also gets rid of waste materials left over also gets rid of waste materials left over from these processesfrom these processes
TRANSPORT OF SUBSTANCES THROUGH THE CELL MEMBRANE
1.1. Passive transportPassive transport
A. Simple diffusionA. Simple diffusion
B. Faciliated diffusionB. Faciliated diffusion
2.2. Active transportActive transport
Passive transportPassive transport
A. SIMPLE DIFFUSIONA. SIMPLE DIFFUSION
Transports small nonpolar Transports small nonpolar molecules, Omolecules, O22, N, N2 2 small uncharged small uncharged polar molecules-water, COpolar molecules-water, CO22
- No Chemical Energy used- No Chemical Energy used
Properties Of Simple Diffusion:Properties Of Simple Diffusion: – Direction (High to Low)Direction (High to Low) – Equilibrium (Equal concentrations)Equilibrium (Equal concentrations)
B. FACILIATED DIFFUSIONB. FACILIATED DIFFUSION
• Faster than simple diffusion and Faster than simple diffusion and occurs via ion channels and carrier occurs via ion channels and carrier proteins. Ions and large polar proteins. Ions and large polar molecules are transported.molecules are transported.
• Usually the systems reserved for Usually the systems reserved for polar and relatively large molecules polar and relatively large molecules but transport smaller ions too – Nabut transport smaller ions too – Na++, , KK++, Ca, Ca2+2+, H, H++
• System uses protein carriers to System uses protein carriers to carry the solute across the carry the solute across the membrane.membrane.
FACILITATED DIFFUSION FACILITATED DIFFUSION
• Higher to Lower (Equilibrium)Higher to Lower (Equilibrium)
• No Chemical Energy usedNo Chemical Energy used
• Major route for GlucoseMajor route for Glucose
ACTIVE TRANSPORTACTIVE TRANSPORT
• Lower to Higher (No Equilibrium) Lower to Higher (No Equilibrium)
• Metabolic Energy used Metabolic Energy used
• Ions, Polar Molecules Ions, Polar Molecules
FACILITATED DIFFUSIONFACILITATED DIFFUSION vs ACTIVE TRANSPORT ACTIVE TRANSPORT
Passive and active transport Passive and active transport compared.compared.
• (A) Passive transport down an (A) Passive transport down an electrochemical gradient occurs electrochemical gradient occurs spontaneously, either by simple spontaneously, either by simple diffusion through the lipid bilayer diffusion through the lipid bilayer or by facilitated diffusion through or by facilitated diffusion through channels and passive carriers. By channels and passive carriers. By contrast, active transport requires contrast, active transport requires an input of metabolic energy and an input of metabolic energy and is always mediated by carriers is always mediated by carriers that harvest metabolic energy to that harvest metabolic energy to pump the solute against its pump the solute against its electrochemical gradient.electrochemical gradient.
• (B) An electrochemical gradient (B) An electrochemical gradient combines the membrane potential combines the membrane potential and the concentration gradient, and the concentration gradient, which can work additively to which can work additively to increase the driving force on an increase the driving force on an ion across the membrane ion across the membrane (middle)(middle) or can work against each other or can work against each other (right).(right).
Permeability of phospholipid Permeability of phospholipid bilayers bilayers
Gases, hydrophobic Gases, hydrophobic molecules, and small molecules, and small polar uncharged polar uncharged molecules can diffuse molecules can diffuse through phospholipid through phospholipid bilayers. Larger polar bilayers. Larger polar molecules and molecules and charged molecules charged molecules cannot. cannot.
Transport of small Transport of small moleculesmolecules
• During passive diffusion, a molecule During passive diffusion, a molecule simply dissolves in the phospholipid simply dissolves in the phospholipid bilayer and diffuses across it bilayer and diffuses across it
• then dissolves in the aqueous then dissolves in the aqueous solution at the other side of the solution at the other side of the membrane membrane
• the direction of transport is the direction of transport is determined simply by the relative determined simply by the relative concentrations of the molecule inside concentrations of the molecule inside and outside of the cell. and outside of the cell.
• The net flow of molecules is always The net flow of molecules is always down their concentration gradient down their concentration gradient from a compartment with a high from a compartment with a high concentration to one with a lower concentration to one with a lower concentration of the molecule. concentration of the molecule.
• No membrane proteins are involved No membrane proteins are involved
Simple diffusionSimple diffusion
Model of an ion channelModel of an ion channel
• In the closed In the closed conformation, the conformation, the flow of ions is flow of ions is blocked by a gate.blocked by a gate.
• Opening of the gate Opening of the gate allows ions to flow allows ions to flow rapidly through the rapidly through the channel.channel.
• The channel The channel contains a narrow contains a narrow pore that restricts pore that restricts passage to ions of passage to ions of the appropriate size the appropriate size and charge and charge
• Ligand-gated channels:Ligand-gated channels: open in open in response to the binding of response to the binding of neurotransmitters or other signaling neurotransmitters or other signaling molecules.molecules.
• Voltage-gated channels: Voltage-gated channels: open in open in response to changes in electric response to changes in electric potential across the plasma membrane potential across the plasma membrane
Simple diffusion - Simple diffusion - Ion channelsIon channels• The best-characterized channel proteins The best-characterized channel proteins
are the are the ion channelsion channels, which mediate the , which mediate the passage of ions across plasma membranes. passage of ions across plasma membranes.
• Ion channels are present in the membranes Ion channels are present in the membranes of all cells.of all cells.
• They have been especially well studied in They have been especially well studied in nerve and muscle, where their regulated nerve and muscle, where their regulated opening and closing is responsible for the opening and closing is responsible for the transmission of electric signals. transmission of electric signals.
Simple diffusion - Simple diffusion - Ion channelsIon channels
• Ion channels form Ion channels form open pores through open pores through the membrane, the membrane, allowing the free allowing the free diffusion of any diffusion of any molecule of the molecule of the appropriate size appropriate size and charge. and charge.
Facilitated Diffusion Facilitated Diffusion • In In facilitated diffusionfacilitated diffusion molecules travel across the membrane molecules travel across the membrane
in the direction determined by their in the direction determined by their concentration gradients.concentration gradients.
• Charged molecules travel across the membrane in the Charged molecules travel across the membrane in the direction determined by the direction determined by the electric potential across the electric potential across the membranemembrane. .
• Facilitated diffusion allows polar and charged molecules, Facilitated diffusion allows polar and charged molecules, such as carbohydrates, amino acids, nucleosides, and ions, to such as carbohydrates, amino acids, nucleosides, and ions, to cross the plasma membranecross the plasma membrane. .
• facilitated diffusion differs from passive diffusionfacilitated diffusion differs from passive diffusion in that the in that the transported molecules do not dissolve in the phospholipid transported molecules do not dissolve in the phospholipid bilayer.bilayer.
Instead, their passage is mediated by proteins that Instead, their passage is mediated by proteins that enable the enable the
transported molecules to cross the membrane without transported molecules to cross the membrane without directly directly
interacting with its hydrophobic interior interacting with its hydrophobic interior
Facilitated diffusion ofFacilitated diffusion of
glucoseglucose • The glucose transporter The glucose transporter
alternates between two alternates between two conformations in which a conformations in which a glucose-binding site is glucose-binding site is alternately exposed on the alternately exposed on the outside and the inside of the outside and the inside of the cell. cell.
• In the first conformation shown In the first conformation shown (A), glucose binds to a site (A), glucose binds to a site exposed on the outside of the exposed on the outside of the plasma membrane. plasma membrane.
• The transporter then undergoes The transporter then undergoes a conformational change such a conformational change such that the glucose-binding site that the glucose-binding site faces the inside of the cell and faces the inside of the cell and glucose is released into the glucose is released into the cytosol (B).cytosol (B).
• The transporter then returns to The transporter then returns to its original conformation (C). its original conformation (C).
• Carrier proteins Carrier proteins
• Needs energyNeeds energy
Active transportActive transport
Carrier proteinsCarrier proteins• Carrier proteins bind specific Carrier proteins bind specific
molecules to be transported on molecules to be transported on one side of the membrane. one side of the membrane.
• They undergo conformational They undergo conformational changes that allow the changes that allow the molecule to pass through the molecule to pass through the membrane.membrane.
• The molecules are then The molecules are then released on the other side.released on the other side.
• Carrier proteins are responsible Carrier proteins are responsible for the facilitated diffusion of for the facilitated diffusion of sugars, amino acids, and sugars, amino acids, and nucleosides across the plasma nucleosides across the plasma membranes of most cellsmembranes of most cells
• The glucose transporter The glucose transporter
provides a well-studiedprovides a well-studied example of a carrier protein.example of a carrier protein.
Classes Classes of of carrier carrier proteinsproteins
UniportUniport (facilitated diffusion) carriers (facilitated diffusion) carriers mediate transport of a single solute. mediate transport of a single solute.
An example is the An example is the GLUT1GLUT1 glucose carrier. glucose carrier.
The ionophore The ionophore valinomycinvalinomycin is also a uniport is also a uniport carrier.carrier.
Uniport Symport Antiport
A A B A
B
A gradient of one substrate, usually an ion, may drive A gradient of one substrate, usually an ion, may drive uphill (against the gradient) transport of a co-substrate. uphill (against the gradient) transport of a co-substrate.
It is sometimes referred to as It is sometimes referred to as secondary active secondary active transporttransport. .
Ex.: Ex.: glucose-Naglucose-Na++ symport symport, in plasma membranes, in plasma membranes of some epithelial cellsof some epithelial cells bacterial bacterial lactose permeaselactose permease, a , a HH++ symport symport carriercarrier..
SymportSymport (cotransport) (cotransport) carriers bind two dissimilar carriers bind two dissimilar solutes (substrates) & solutes (substrates) & transport them together transport them together across a membrane. across a membrane.
Transport of the two solutes is Transport of the two solutes is obligatorily coupledobligatorily coupled. .
A substrate binds & is transported. Then another A substrate binds & is transported. Then another substrate binds & is transported in the other substrate binds & is transported in the other direction. direction.
OnlyOnly exchange exchange is catalyzed, not net transport. is catalyzed, not net transport.
The carrier protein cannot undergo the The carrier protein cannot undergo the conformational transition in the absence of bound conformational transition in the absence of bound substrate. substrate.
Antiport (exchange diffusion) carriers exchange one solute for another across a membrane.
Usually antiporters exhibit "ping pong" kinetics.
Example of an antiport carrier: Example of an antiport carrier:
Adenine nucleotide translocaseAdenine nucleotide translocase (ADP/ATP (ADP/ATP exchanger) catalyzes 1:1 exchange of ADP for exchanger) catalyzes 1:1 exchange of ADP for ATP across the inner mitochondrial ATP across the inner mitochondrial membrane. membrane.
ATP 4
ADP 3
mitochondrial matrix
adenine nucleotide translocase
Active transportActive transport enzymes couple net solute enzymes couple net solute movement across a membrane to movement across a membrane to ATP ATP hydrolysishydrolysis. .
An active transport pump may be a An active transport pump may be a uniporteruniporter or an or an antiporterantiporter..
S1 S2
ATP
ADP + Pi
Side 1 Side 2
ActiveTransport
Model of active transport: Energy derived from the hydrolysis of ATP is used to transport H+ against the electrochemical gradient (from low to high H+ concentration). Binding of H+ is accompanied by phosphorylation of the carrier protein, which induces a conformational change that drives H+ transport against the electrochemical gradient. Release of H+ and hydrolysis of the bound phosphate group then restore the carrier to its original conformation.
Active transport of glucose Active transport driven by the Na+ gradient is responsible for the uptake of glucose from the intestinal lumen. The transporter coordinately binds and transports one glucose and two Na+ into the cell. The transport of Na+ in the energetically favorable direction drives the uptake of glucose against its concentration gradient.
NaNa++-K-K++ PumpPump
• ENDOCYTOSIS :ENDOCYTOSIS : – Pinocytosis (Fluid & Adsorptive)Pinocytosis (Fluid & Adsorptive) – PhagocytosisPhagocytosis
• EXOCYTOSIS:EXOCYTOSIS:
ENDOCYTOSIS vs EXOCYTOSIS ENDOCYTOSIS vs EXOCYTOSIS
Example of ENDOCYTOSIS :Example of ENDOCYTOSIS :
Phagocytosis of bacteriaPhagocytosis of bacteria
Glut-2
G-6-P
ATPADP
Glucose
Voltage dependent Ca2+ channel
Ca2+KATP
Membrane depolarisation
closed
Example of ExocytosisExample of Exocytosis
TRA
FFICK
ING
Insulin granules
SU
Insulin exocytosisInsulin exocytosis
CytoplasmCytoplasm
•Thick clear, amorphous fluid Thick clear, amorphous fluid that surrounds the nucleusthat surrounds the nucleus
•Contains all of the material Contains all of the material needed by the cell to conduct needed by the cell to conduct life processeslife processes
•Fluid in cytoplasm is Fluid in cytoplasm is constantly moving and constantly moving and suspends other parts of the cellsuspends other parts of the cell
The cytoplasmThe cytoplasm
• contains membranes and organelles contains membranes and organelles suspended in a clear liquid called suspended in a clear liquid called cytosol.cytosol.
• also contains abundant protein rods also contains abundant protein rods and tubules that form a supportive and tubules that form a supportive framework called the cytoskeleton.framework called the cytoskeleton.
• encircled by a thin membrane known encircled by a thin membrane known as plasma membraneas plasma membrane
RibosomesRibosomesFunction: Synthesize proteinsFunction: Synthesize proteins
Golgi apparatusGolgi apparatus Function: Packages and modifies Function: Packages and modifies
protein molecules for transport and protein molecules for transport and secretionsecretion
MitochondriaMitochondria
Function: known as ‘power house’ of theFunction: known as ‘power house’ of the
cell. release energy from food molecule cell. release energy from food molecule
and transform energy into usableand transform energy into usable
formform
LysosomesLysosomes
Function: contain enzymes capable of Function: contain enzymes capable of digesting worn cellular parts or substancedigesting worn cellular parts or substancethat enter cells.that enter cells.
PeroxisomePeroxisome
Function: contain enzymes called peroxidases, Function: contain enzymes called peroxidases, important in the breakdown of manyimportant in the breakdown of manyorganic molecules.organic molecules.
CentrosomeCentrosome
Function: helps distribute Function: helps distribute chromosomes to chromosomes to
new cells during cell reproduction and new cells during cell reproduction and
initiates formation of cilia.initiates formation of cilia.
The nucleusThe nucleus• Relatively large in size and spherical in shape.Relatively large in size and spherical in shape.
• Enclosed in a double layered nuclear envelop which Enclosed in a double layered nuclear envelop which consist of an inner and an outer lipid bilayer membrane.consist of an inner and an outer lipid bilayer membrane.
• These two membranes have a narrow space between These two membranes have a narrow space between them, but are joined at places that surround relatively them, but are joined at places that surround relatively large openings called nuclear pores.large openings called nuclear pores.
• The nuclear pores consist of more than 100 different The nuclear pores consist of more than 100 different types of proteins that allow substances to move types of proteins that allow substances to move between the nucleus and the cytoplasm, eg., messenger between the nucleus and the cytoplasm, eg., messenger RNA.RNA.
• The nucleus contains a fluid (nucleoplasm) in which The nucleus contains a fluid (nucleoplasm) in which other substances float:other substances float:
1. Nucleolus1. Nucleolus 2. Chromatin2. Chromatin
The Nucleus The Nucleus
The Nucleus The Nucleus • Centrally located spherical cellular Centrally located spherical cellular
component which carries hereditary component which carries hereditary material ---- the DNA and controls all the material ---- the DNA and controls all the vital activities of cytoplasm.vital activities of cytoplasm.
• Nuclear envelope and nucluoplasmNuclear envelope and nucluoplasm
Double-layered membrane --- Inner Double-layered membrane --- Inner membrane and Outer membrane. membrane and Outer membrane. Membrane is interrupted with pores.Membrane is interrupted with pores.
Nucleoplasm is rich in molecules for DNA Nucleoplasm is rich in molecules for DNA replication, transcription and RNA replication, transcription and RNA production production
The NucleusThe Nucleus
• Composition of the nucleusComposition of the nucleus– a. Nucleic acidsa. Nucleic acids– b. Proteinb. Protein– c. Enzymesc. Enzymes– d. Surrounded by a double-d. Surrounded by a double-
layer membranelayer membrane
CHROMOSOMESCHROMOSOMES
CHROMOSOMES consist of chromatins extensively folded into loops. Each chromosome contains a single DNA molecules with associated proteins. Chromosomes are only visible during mitosis and meiosis when their chromatin condenses.
CHROMOSOMESCHROMOSOMES
NUCLEIC ACIDSNUCLEIC ACIDS
THERE ARE TWO DIFFERENT THERE ARE TWO DIFFERENT
TYPES OF NUCLEIC ACIDS,TYPES OF NUCLEIC ACIDS,
DNADNA AND AND RNARNA..
• The nucleotides form a double helix.
• The function of DNA is The function of DNA is serve as the basis of serve as the basis of the genetic code.the genetic code.
• DNA contains the DNA contains the “instructions” for “instructions” for building the proteins building the proteins needed by the cell.needed by the cell.
• all DNA is restricted to all DNA is restricted to the nucleus. the nucleus.
DNA (Deoxyribonucleic acid )DNA (Deoxyribonucleic acid )
DNADNA
DNA is composed of
• a phosphate group
• a deoxyribose sugar and
• 4 nitrogen bases (A, C, G, T).
In this formation: A bonds with T& C bonds with G only.
RNA
• It is a linear molecule similar to DNA except that it is single stranded and contains ribose instead of deoxyribose and Uracil in place of thymine.
•RNA is synthesized by the transcription of DNA catalyzed by RNA polymerase I, II and III.
RNARNA
There are three types of RNA molecules There are three types of RNA molecules that that
function in the cytoplasm of The cell: function in the cytoplasm of The cell:
1.1. Messenger RNA,Messenger RNA,
2.2. Transfer RNA, ANDTransfer RNA, AND
3.3. Ribosomal RNA.Ribosomal RNA.
RNA - 3 typesRNA - 3 types
1. mRNA carries the genetic code to the cytoplasm to direct the protein synthesis.
2. tRNA associated with specific amino acid that has been activated by enzyme.
3. rRNA associates with mRNA and tRNA during protein synthesis.
RNARNA
THE FUNCTION OF RNATHE FUNCTION OF RNA
IS TO IS TO SYNTHESIZE SYNTHESIZE
PROTEINSPROTEINS USING THE USING THE
GENETIC CODE OF DNA.GENETIC CODE OF DNA.
RIBOSOMESRIBOSOMES
RIBOSOMES ARE THE SITERIBOSOMES ARE THE SITE
OF PROTEIN SYNTHESISOF PROTEIN SYNTHESIS
RIBOSOMESRIBOSOMES
CAN BE LOCATED FREE IN THECAN BE LOCATED FREE IN THE
CYTOPLASM OR ASSOCIATEDCYTOPLASM OR ASSOCIATED
WITH THE ENDOPLASMICWITH THE ENDOPLASMIC
RETICULUMRETICULUM
RIBOSOMESRIBOSOMES
Organelles - RibosomesOrganelles - Ribosomes
• Structurally the ribosome consists of a Structurally the ribosome consists of a small and larger subunit.small and larger subunit.
M/A of AminoglycosidesM/A of Aminoglycosides
