SEL:Teori, Struktur, Organela

drg. Amandia Dewi Permana Shita, M.Biomed

Cell Theory

• 1600’s- the invention of the microscope, in 1665

• An Englishman Robert Hooke first observed cork cells and he reported to the world that life’s smallest structural units were “little boxes” or “cells”

Cell Theory

1675. The Dutch amateur scientist Anton van Lieuwenhoek first :

– Observed living cells in pond water, rainwater and in material scraped from his teeth.

– He drew the basic form of bacteria as coccus, rods and spiral

Paramecium

Diatoms

Cell Theory

1838: German botanist Schleiden:concluded that all plants are made of cells.ONION CELLS

Schleiden

Cell Theory

1839. German biologist Theodor Schwann stated thatall animals are made of cells.

A. Gut B. brain C. bone marrow d. cartilage e. muscleF. kidney

Cell Theory

Cell is the smallest unit of life.Every living thingis made up of oneor more cells. Human Liver Cells

Human skin cell

•Humans have an estimated 100 trillion cells.•The largest known cell is an unfertilized egg cell

Cell Theory• Until the second half of the

19th century many scientists and philosophers believed that some form of life could arise spontaneously from nonliving matter spontaneous generation.

• 1855. German physician Rudolf Virchow concluded that all cells come from existing cells (omnis cellula ex cellula) The Theory of Biogenesis Mitosis: Cell Division

Cell Theory

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

In 1953 Watson and Crick made their first announcement on the double-helix structure for DNA. Vital functions of an organism occur within cells, and all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cell

All cells have several different abilities: (Mashburn et al, 1996)

• Reproduction by cell division: (binary fission/mitosis or meiosis).

• Use of enzymes and other proteins coded for by DNA genes and made via messenger RNA intermediates and ribosomes.

• Metabolism, including taking in raw materials, building cell components, converting energy, molecules and releasing by-products.

• Response to external and internal stimuli such as changes in temperature, pH or levels of nutrients.

• Cell contents are contained within a cell surface membrane that is made from a lipid bilayer with proteins embedded in it.

Cell TypesCell TypesProkaryotes:Prokaryotes:Eukaryote:Eukaryote:

Cell Types

A.Prokaryotes:

• Bacteria & Archae• Have no nucleus or

membrane-bound organelles.

• Outside: flagella or pilli• Enclosing: envelope cell

wall• Inside: - Cell genome (circular molecule) - Extrachromosomal DNA (plasmid) - 50S+30S ribosome• RNA/protein synthesis

coupled in cytoplasm

Structure External to the Cell Wall

FLAGELLA Flagella are relatively long

filamentous appendages consisting of a filament, hook and basal body

Prokaryotic flagella rotate to push the cell, facilitate movement and communication between cells.

Flagellar (H) protein functions as an antigen flagellin

Structure External to the Cell Wall

FIMBRIAE (PILI) Many Gram negative bacteria possess

rigid surface appendages,shorter and thinner than flagella called pili or fimbriae

They are composed of structural protein subunits termed pilins

Minor protein located at the tips of pili, are responsible for the attachment properties

Two classes can be distinguished : ordinary pili, which play a role in the adherence of symbiotic and pathogenic bacteria to host cells, and sex pili, which are responsible for the attachment of donor and recipient cells in bacterial conjugation

The Cell Wall Gram-positive cell walls consist

of many layers of peptidoglycan and also contain teichoic acids

Gram-negative bacteria have a lipopolysaccharide-lipoprotein-phospholipid outer membrane surounding a thin peptidoglycan layer

The outer membrane protects the cell from phagocytosis and from penicillin, lysozyme and other chemicals

Porins are proteins that permit small molecules to pass through the outer membrane.

The lipopolysaccharide consists of sugar (O polysaccharides) that function as antigens and lipid A, which is an endotoxin

Cell Types. Eukaryotes: contains membrane

bound nucleus and organelles. Nucleus contain DNA (linear molecule with histone protein)

Some eukaryotic organelles such as mitochondria contain some DNA

RNA synthesis inside the nucleusProtein synthesis in cytoplasm

Protist, fungi, plant, animal

Eukaryotic vs prokaryotic cells

Prokaryotes:

• no membrane-bound nucleus

• transcription and translation are coupled

Eukaryotes:

• DNA is located in membrane-bound nucleus

• Transcription and translation are separated in space and time

THE SIMILARITY BETWEEN PROKARYOTES AND

EUKARYOTES

OrganelleOrganelle

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-- ++

-- ++

-- ++

-- ++

EUKARYOTESPROKARYOTES

Endomembrane

Nuclear membrane

Mitochondria/Chloroplast

Golgi Apparatus

Endoplasmic Reticulum

THE DIFFERENCES BETWEENPROKARYOTES AND

EUKARYOTES

Cell divisionBinary fission (simple division)

Mitosis (fission or budding)Meiosis

Prokaryotes Eukaryotes

Typical organism bacteria Protist, fungi, plants, animals

Typical size ~1-10 μm ~10-100 μm

Type of nucleus Nucleoid region; no real nucleus

Real nucleus with double membrane

DNA Circular (usually) Linear molecules

RNA-/protein synthesis

Coupled in cytoplasm RNA_synth inside the nucleus; protein synth. In cytoplasm

ribosomes 50S + 30 S (70S) 60S + 40S (80S)

Eukaryotic Cell Types : Animal vs. Plant

Cell Types : Animal vs. Plant

1. Plant cells have chloroplasts

2. Plant cells have a cell wall

3. Plant cells have a large central vacuole

4. Animal cells have more lysosomes and vesicles

Cell OrganellesCell Organelles

Cell Organelles• Organelle= “little organ”• Found only inside

eukaryotic cells• All the stuff in between

the organelles is cytosol that contain thousands of enzymes .

• Everything in a cell except the nucleus is cytoplasm

Cell Anatomy• Cell membrane

– The outer layer of animal cells, found inside cell walls (if wall is present)

– Controls what enters and leaves the cell

– outside boundary– gives shape and flexibility– semi-permeable– made of lipids in 2 layers/

Phosoplipid bilayer– Protect cytoplasm & nucleus

• Cell recognition and attachment involves membranes

• Many metabolic functions, such as oxidative phosphorylation, are organized around membranes

• Signal systems for cell regulation are based upon membranes

A membrane around the cell is necessary for many reasons

Cell Membrane

1. Integral membrane protein to active transport.

2. Trans-membrane protein/ peripheral protein

Protein Transmembran

Transport zat

Phospolipid

•Protein tertanam pd lap lipid protein transmembrane•Protein yg mengapung diantara lipid protein integral•Proteins yg tdpt pd bag luar lipid bilayer peripheral

Nucleus• Control center of the cell• Contains DNA• Surrounded by a double

membrane• Usually the easiest

organelle to see under a microscope– Contains DNA

found on chromatin strands

– Materials pass in and out through the nuclear membrane

Fungsi nukleus

• Menyimpan gen pada kromosom

• Mengatur gen dlm kromosom dlm proses pembelahan sel

• Mentransport faktor regulasi & produk gen melewati pori inti

• Menghasilkan pesan (mRNA) yang mengkode protein

• Menghasilkan ribosom dalam nukleus

• Mengatur DNA uncoiling dlm replikasi gen

Nukleolus (anak inti)

• Tdpt 1 / lebih, tdpt di dlm nukleus

• Bbtk sferik sbg massa granul & fiber yg pekat

• Merupakan tempat kromosom dg banyak kopi gen yg diperlukan utk sintesis ribosom, RNA & protein ribosom. Pd sel sehat dihasilkan 10.000 ribosom per menit.

Mitochondria – Rod-shaped– Create energy for the cell from food– Converts the chemical energy

stored in food into compounds more convenient for the cell to use.

– Tempat respirasi seluler proses katabolik yg menghasilkan ATP dg mengekstraksi energi dari gula, lemak dan bahan bakar lain dgn bantuan oksigen.

– Bukan bagian dari sistem endomembran

– Memiliki ribosom dan DNA dlm jumlah sedikit. DNA inilah yg memprogram sintesis protein yg dibuat dlm ribosomnya sendiri

The Mitochondrial

• Most of our body ’s nucleated cells contain 500 to 2000 mitochondria

• In the cone cell photoreceptors of the eye, mitochondria make up 80% of the intracellular volume.

• In extra-ocular muscles, they account for 60%, and in heart muscle they comprise 40% of the volume of the cell.

• Nerve cells in the brain and muscles require a great deal of energy, and thus appear to be particularly damaged when mitochondrial dysfunction occurs.

The Mitochondrial • In matrix the oxidation phosphorylation takes place.• The Kreb Cycle takes place in the matrix .• It contains three major proteins : 1) The electrone transport

chain protein complex (I-IV). 2) an enzyme complex called ATP synthetase which makes ATP (V) and 3). transport proteins which regulate the transfer of molecules into and out of the matrix.

The Mitochondrial Chromosome

• Mitochondria consist of 2 – 10 mtDNA Egg cytoplasma 200.000 – 300.000 mtDNA increase

during oogenesis• mtDNA was found to vary according to cell type

– Low in platelets (Platelets have only two to six mitochondria).

– Red blood cells do not contain mitochondria• Highest in brain, liver, kidney

Endoplasmic Reticulum

• Carry proteins and other materials through the cell

• Connected to nuclear membrane

• Highway of the cell• Rough ER: studded with

ribosomes; it makes proteins

REK menghasilkan protein & menyusun membran

• The rough ER manufactures membranes• Ribosomes on its surface produce proteins

1 2

3

4Transport vesiclebuds off

Ribosome

Sugarchain

Glycoprotein

ROUGH ER

Polypeptide

Secretory(glyco-) proteininside transportvesicle

REH memiliki fungsi bervariasi

• Smooth ER synthesizes lipids

• In some cells, it regulates carbohydrate metabolism and breaks down toxins and drugs

Ribosome • Ribosome60S+40S• Found attached to

rough ER or floating free in cytosol

Site of protein Site of protein synthesissynthesis

Produced in a part of Produced in a part of the nucleus called the nucleus called the the nucleolusnucleolus

Ribosom & Sintesis Protein

Ribosom

• Pabrik utk sintesis protein

• Dibangun dr molekul2 protein & rRNA

• Pd sel prokariot, ribosom tdpt bebas dlm sitosol. Dlm sel eukariot ribosom tdpt bebas di sitosol, matriks mitokondria, stroma kloroplas, atau menempel pd permukaan selaput RE

• RE kasar adl RE yg dilekati bnyk ribosom, RE halus tidak mengandung ribosom

Ribosom

• Ribosom tdr atas 2 bag tdk sama besar

• Ukuran ribosom ditentukan dg analisis sedimentasi dg mengukur laju pengendapan dlm larutan kental (mis sukrosa) dg pemusingan kecepatan tinggi.

• Koefisien sedimentasi ditentukan dg S (Svedberg) nama penemu ultracentrifuge

• Ribosom prokariot memiliki koefisien sedimentasi 70S, ribosom eukariot

memiliki koefisien sedimentasi 80S

Ribosom

• Ribosom prokariot tdr atas sub unit besar 50S & sub unit kecil 30S

• Ribosom eukariot tdr atas sub unit besar 60S & sub unit kecil 40S

• Ribosom mitokondria & kloroplas juga tdr atas 2 sub unit. Ribosom mitokondria bervariasi dr ukuran 55S pd hewan sampai 80S pd bbrp protozoa & jamur. Ribosom kloroplas adalah 70S pd semua sel hijau

Golgi Apparatus

• Finish, sort, and “ship” many products of the cell

• Synthesize macromolecules• Store and export products of E.R.• Deskripsi :

Klp 5-8 kantung membran bbtk mangkuk ( cisternae ) dg ujung menggelembung & menempel satu sama lain.

Golgi Apparatus

Golgi aparatus

• Bdn golgi bbtk polar, tdr atas bagian cis dmn protein masuk, & bagian trans dmn protein keluar.

• Dibagi2 dlm kompartemen/ruang2 yg berbeda dg processing enzymes yg spesifik.

• ± tdpt 20 bdn golgi pd tiap sel, vary depending on the function of the cell

What does it do?

• Utk distribusi & pusat lalulintas produk kimia sel.

• Memodifikasi protein & lipid & prepares them for exportation.

• Uses sugar nucleotides to transport the proteins.

What else does it do?

• It works with the endoplasmic reticulum.

• It uses a Trans Golgi Network (TGN) to attach chemical “flags” on the exported proteins as sort of an address code so that they get to the right place in the cell.

What’s so Great about it?

• Without the Golgi Apparatus, cells could not secrete important chemicals into our bodies such as:

Hormones Enzymes (create chemical reactions)Antibodies ( keep us from getting ill

and possibly dying)

Golgi Golgi ApparatusApparatus

Golgi BodyGolgi Body Flattened sacsFlattened sacs Receive Receive

proteins and proteins and other material, other material, package them package them and ship them and ship them outout

Golgi Apparatus

Lysosomes

• Lysosome– Contain enzymes that

function in digestion of food and dead cell parts (break down & worn out organelles)

– Surrounded by a membrane

– Small organelles filled with enzymes,

Lysosomes• Large vesicles

formed by the Golgi

• Garbage disposal of the cell

• Contain digestive enzymes that break down wastes

Which organelles do lysosomes work with?

Peroxisomes• They are similar to lysosome but smaller.• Mengandung enzim yg mentransfer hidrogen dari berbagai substrat

ke oksigen, yg menghasilkan H2O2 sbg produk samping.• Bbrp peroksisom menggunakan O2 utk memecah as.lemak mjd

molekul yg lbh kecil utk diangkut ke mitokondria sbg bahan bakar utk respirasi seluler.

• Found mainly in liver and kidney cells• Main function is detoxification of toxic materials.• Dlm hati menawarkan racun alkohol & senyawa berbahaya

lainnya dgn mentransfer hidrogen dari racun ke oksigen. H2O2 yg terbentuk tsb sebenarnya beracun, namun organel ini mengandung suatu enzim yg mengubah H2O2 menjadi air.

• Pada tumbuhan glioksisom ditemukan dlm jaringan penyimpan lemak dari biji tumbuhan mengandung enzim yg menginisiasi pengubahan as.lemak mjd gula, yg dpt digunakan oleh biji yg sedang tumbuh sbg sumber energi & sumber karbon sampai biji tsb dpt menghasilkan gula sendiri melalui fotosintesis

Cytoskeleton Roles of the Cytoskeleton: Support, Motility,

and Regulation• Acts as skeleton and muscle• Provides shape and structure

penting utk sel hewan yg tdk memiliki dinding sel

• Utk pergerakan organel2 didalam sel

• Motilitas sel interaksi antara sitoskeleton dg protein (molekul motor) mikrotubul & mikrofilamen

• Made of three types of filaments

Components of cytoskeleton: 1) Microfilaments (Filamen aktin)

• Batang padat, berdiameter 7 nm. Filamen ini tdd molekul aktin (suatu protein globular)

• Merupakan rantai ganda subunit aktin yg terlilit.

• Peran: menahan tegangan (gaya tarik) mendukung bentuk sel

• Sebagai bagian alat kontraksi sel otot bersamaan dg miosin

Components of cytoskeleton: 2) Intermediate filaments

Intermediate filaments

- Dinamai berdasarkan diameternya, lbh kecil drpd mikrotubula, lbh besar drpd mikrofilamen.

- Spesialisasi utk menahan tarikan. Sangat penting utk dlm memperkuat bentuk sel dan menetapkan posisi organel tertentu

Components of cytoskeleton: 3) Mikrotubula

• Memberi bentuk & mendukung sel, juga sbg jalur yg digunakan organel (yg dilengkapi dg molekul motor) utk dpt bergerak

• Misal: menuntun vesikula sekretori dari AG ke membran plasma

• Terlibat dlm pemisahan kromosom selama pembelahan sel

Cell Wall

• Cell Wall – rigid layer of nonliving

material– Provide protection &

support– Found in plant, some

bacteria, some protists and some fungi

Chloroplast• ChloroplastContains the

green pigment chlorophyll• Site of food (glucose)

production• Turn the Sun’s energy into

food through photosynthesis

• They do not make energy, they convert it

Vacuoles• Vacuole

– Store food water and other materials

– Small in animal cell – Large in plants

• Store H2O

• Help keep the plant upright

Vacuoles

• Large central vacuole usually in plant cells

• Many smaller vacuoles in animal cells

• Storage container for water, food, enzymes, wastes, pigments, etc.

Membrane Cell

Vakuola

Plastida

Endoplasmic R

Golgi Apparatus

Cell wall

PLANT CELL

Sel tumbuhan berbeda dr sel hewan, krn tdk memp.: sentriol & filamen intermediat, namun memp. Plastida, ddg sel & vakuola berukuran besar.