BIOLOGI SEL

History Theory Cell Types

History of Cytology  Initial microscopes Robert Hooke (1665)  Origin of term cell Antoni Van Leeuwenhoek  First to visualize living cells  Cell Theory developed by Schleiden (1838), Schwann(1839) and Virchow (1855) Every organism is composed of 1+ cells A cell is the simplest unit to demonstrate the properties of life Cells arise only from previously existing cells

 Light Microscope: First cells observed by Robert Hooke in 1665 using a light microscope. First cells observed by Robert Hooke in 1665 using a light microscope. How We Study Cells Simple vs. Compound? Simple vs. Compound?

 The electron microscope (EM) uses a beam of electrons  It has a higher resolving power than the light microscope.

 The scanning electron microscope (SEM) is used to study the detailed architecture of the surface of a cell. Figure 4.2B (b) Scanning electron micrograph (SEM) of a white blood cell

 The transmission electron microscope (TEM) is useful for exploring the internal structure of a cell. Figure 4.2C (c) Transmission electron micrograph (TEM) of a white blood cell

Definisi Sel : Sel adalah unit terkecil yang mampu melakukan fungsi-fungsi kehidupan Mengapa Sel Berukuran kecil ? Sel berukuran besar,lebih sedikit interaksinya dgn lingkungan Peningkatan ukuran sel, maka volume meningkat lebih cepat Nukleus menjaga aktivitas seluler, jika ukuran sel besar,maka bagian2 sel lain jauh jaraknya. Berfungsi lebih efisien

Ukuran dan Bentuk SeL

Measurements 1 centimeter (cm) = 10  2 meter (m) = 0.4 inch 1 millimeter (mm) = 10 –3 m 1 micrometer (µm) = 10 –3 mm = 10 –6 m 1 nanometer (nm) = 10 –3 mm = 10 –9 m

Cell diversity  Procaryotes- Eubacteria and Arhaebacteria  Eucaryotes- Protista, Fungi, Plants and Animals  Similarities:  Similarities: Procaryotes and eucaryotes Cell membrane energy metabolism Genetic code  Differences: Procaryotes are unicellular Except for many members of protista the rest of eukaryotes are multicellular Size: procaryotes um, eucaryotes um Membrane bound organelles present in eucaryotes but not procaryotes Reproduction: cell fission in procaryotes vs mitosis in eukarotes

Properties of Cells Properties… Interaction with the environment All have transmittable genetic program – DNA: similar structure and function, being inherited – Genes: units of genetic function, basic similarity – Evolution: plasticity of genetic information, functional divergence in response to environmental cues Energy biogenesis Similarity of metabolic pathways, eg. glycolytic pathway, Krebs cycle, adaptive variations on a general theme Use of ATP as the universal cellular energy currency  Chemical and mechanical activity Similar enzymes carry out metabolic reactions → energy Use of energy to do mechanical work

Cellular Classification Prokaryotes- before nucleus NO nucleus (nucleoid region) NO organelles Single, circular DNA Smaller, less complex E.g bacteria, archaea Eukaryotes- true nucleus Nucleus Membrane bound organelles DNA arranged on multiple chromosomes Larger E.g protists, fungi, plants, animals

Basic Cell Organization  Membrane  Nucleus  Cytoplasm  Organelles

Struktur bakteri( E. coli)  Kapsul*  Dinding sel  Membran  DNA  Ribosom  Pili, * flagella *

Procaryotes: Structure  Bacteria have appendages with specific functions – Flagella, composed of flagellin helps bacteria move – Fimbriae are small bristlelike fibers that allow bacteria to attach themselves to surfaces – Sex pili (F pilus) used for conjugation to transfer DNA from one bacterium to another  Genes coding for F-pilus are on F plasmid

Kapsul

Lapisan lendir

PILI

Procaryotes: Structure Cell wall: used for protection, shape, rigidity  Composed of peptidoglycan, a polysaccharide of alternating acetlylated muramic acid (N-AM) and glucoseamine (N-AG)  β1  4 glycosidic bond btw sugars  cross-linked by a short oligopeptide

G- bacteria G+ bacteria Two types of bacteria based on cell wall structure Gram positive: multiple layers of peptidoglycan Gram negative: few layers of peoptidoglycan

Perbedaan Bakteri Gram Positif & Gram Negatif  Bakteri Gram Positif : Staphylococcus  Bakteri Gram Negatif : Salmonella

Plasma Membrane: Overview STRUCTURE  Flexible barrier  Made of PhosphoLipids-double layer  Contains Proteins FUNCTION  Protect inside of cell  Contacts other cells  Identifies cell  Regulates entry and exit

Procaryotes: Structure Plasma membrane Beneath the cell wall is the plasma membrane, a phospholipid bilayer with associated proteins Steroid like molecules instead of cholesterol

Cytoplasm = Cytosol (fluid) + Organelles (structures with roles)  Mostly water  Lots of chemical reactions happen here

Organelles (structures of cytoplasm)  Cytoskeleton  Ribosomes  Endoplasmic Reticulum  Golgi Complex  Lysosomes, Peroxisomes, Proteasomes  Mitochondria

Eukaryotic Cell Types Plant Animal

Eucaryotic cells Diversity Protista: free-living marine unicellular, some photosynthetic  e.g. Giardia lamblia, dinoflagellates, Paramecium, Plasmodium  Multicellular organisms Fungi, Plants, Animals Differentiation Model organisms (a) Saccharomyces cerevisiae (yeast) (b) Arabidopsis thaliana (c) Caenorhabditis elegans (d) Drosophila melanogaster (e) Mus musculus

Eucaryotic cells Structure Characteristics:  Typically um  Separation of DNA and cytoplasm by nuclear envelope  Presence of membrane-bound compartments with specialized functions: Mitochondria, chloroplasts, ER, Golgi complex  Highly specialized motor proteins  Nuclear envelope and internal membranes Originated from cell membrane differentiated and acquired special functions

Eucaryotic cells  organelles can be divided into four categories The nucleus and ribosomes endomembrane system energy-related organelles cytoskeleton

KarakteristikProkariotikEukariotik Ukuran selumumnya 0,5-5 μm μm Inti selTidak terbungkus membran inti sehingga tidak disebut nukleus tetapi nukleiod Inti sejati yang terbungkus membran inti dan memiliki nukleolus Organel yang terbungkus membran Tidak ada Ada, seperti lisosom, kompleks golgi, mitokondria, retikulum endoplasma, dan kloroplas FlagelTersusun atas 2 berkas protein Lengkap, tersusun atas mikrotubulus rangkap GlikokaliksAda, berupa kapsul atau lapisan lendir Ada pada sel yang tidak memiliki dinding sel Dinding sel ada, tersusun atas peptidoglikan Jika ada, struktur kimia sederhana Vesikel gasAdaTidak Membran selTanpa karbohidrat dan biasanya tanpa sterol Sterol dan karbohidrat ada sebagai reseptor SitoplasmaTanpa sistoskeleton atau aliran sitoplasmik Ada sistoskeleton dan terjadi aliran sitoplasmik RibosomUkuran kecil (70s)Ukuran besar (80s) Kromosom (DNA)Kromosom tunggal melingkar tanpa protein histon Kromosom linear melipat dengan terikat protein histon Pembelahan selPembelahan binerMitosis Rekombinasi seksual Tanpa meiosis, hanya transfer fragmen DNA Meiosis Sensitivitas terhadap antibiotik SensitifTidak sensitif