Hakim Sabzevari University, Dr M.R.Vaezi 17/04/2013 K.

اازۀ ه ز و اا Structure and Function of Cells

ن و ل ه

هﮥ دات از ل ا ر ل: ل وا ز ت ا. ر ل ن : • ل وا ز ت ا • هﮥ ه ز از ل ا • ل ه از ل ه از د اد • ل ه از واه ا اودن . .

د ا ل ه ا هﮥ دات از ل ا

ل ه ااز ل اا : • ل ه در ل ل • ل ه ا ب و ا، ر ا دد

1 Hakim Sabzevari University, Dr M.R.Vaezi 17/04/2013 K.

وپ از ده ل ه را راﮥ

وپ ر ( Compound light microscope) – ه رت را اا ده • ا ر را از ر ده • ا را رگ • را ر وپ او ( Electron microscope) – رت در ن از وپ ر ا

• وپ او ا ( (Transmission electron microscope (TEM ): اون ه از ر

• وپ او رو ( (Scanning electron microscope (SEM ): اون ه ا را د و

ﮥ وپ

ه ل ه اا دار

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-1 ه ل ه ( Membrane ) دار

Phospholipid Bilayer

2 - ه ل ه ( Cytoplasm ) دار Cytoplasm

Plasma Membrane Exterior (exocellular)

-1 ه ل ه -3 ه ل ه ّ و، و دارا RNA و DNA هرات دار ه

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Prokaryotic Cells ااز ل ر ( Eukaryotic Cell) 1. ان ه ر در در ا 2. از ل ه ر ل ور ( Prokaryotic Cell) 3. دا وزوم د ( DNA ) 4. دا هاران رزوم ا در 5. ان اا در 6. ( دو = binary fission) 7. د 8. ه دارا Pili و و ل ودار

Prokaryotic Archaea and Bacteria Cell • دو دو از ل ه ور Structure • ه را ه • در ز اد ا اه دار • د دو • ً از ل ه ر

Eukaryotic Cell

Most kinds of living organisms • Protozoans • Algae • Fungi • Plants • Animals

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Eukaryotic Cells Animal Cell Anatomy

1. ل ه ر دو از ل ه ه 2. دا ه و ا ، ل ل را 3. دا ه ر در وزو درون ن ن ار دار ( وزوم) 4. ا 5. دارا اا ( ) ر در ه – ا اا در ار و ه ن و و و ا دار

Plant Cell Anatomy Functions of Cells

1. ل ه وا ا ت را ده 2. و اام ه را ده 3. ال ور ن را ام ده – ه و و ه – اژ – ( ل ه ) – ( ل ه ) – زدا ( ل ه ) – د اد زا ( ل ه و ) و

Organelles of a Typical Cell ور ل • Production of – located ° The cell is the basic unit of structure and function attached to ER or free-floating in the body. Endoplasmic • Passageway for materials – Prokaryote v. Eukaryote Reticulum (ER ) • Are smaller than eukaryotic cells *Rough • Produces proteins & processes • Lack internal structures surrounded by membranes molecules for secretion • Lack a nucleus *Smooth • Produces lipids & detoxifies ° There are three principal parts: drugs & stores Ca ++ – plasma membrane (plasmalemma) • Packages material for export & – cytoplasm and organelles processes macromolecules – nucleus.. & vesicle • Storage..

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The Nucleus Contains the Cell’s Genetic • Contains digestive enzymes. Each Information contains one specific enzyme. Nucleus contains chromatin, a network of • Carries out photosynthesis:

6CO 2 + 6H2O C 6H12 O6 + 6O2 strands that condenses to form chromosomes • Chromosomes contain DNA which carries genes, the units of heredity Mitochondria • Aerobic cellular respiration: C6H12 O6 + 6O2 6CO 2 + 6H2O +ATP

Cilia, flagella, • Surface projections – increase microvilli surface area & produce movement..

The Nucleus Contains the Cell’s Genetic Information Nucleus contains chromatin, a network of strands that condenses to form chromosomes • Chromosomes contain DNA which carries genes, the units of heredity • - dark region of chromatin with ribosomal RNA (rRNA) • Nuclear envelope separates the nucleus from the cytoplasm, but has nuclear pores to permit passage of ribosomal subunits

Anatomy of the Nucleus Organelles

Endomembrane system: • (smooth and rough) • Golgi apparatus •

Energy-related organelles : • Mitochondria • Chloroplasts

Storage organelles: • •

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Endoplasmic Reticulum (ER)

• Rough • non-membrane-bound particles – Ribosomes attach • Synthesize proteins – synthesis • On rough ER • Smooth – No ribosomes – Lipid synthesis – Carbohydrate synthesis

Animal Cell Anatomy Rough ER (RER) and Smooth ER (SER)

Function of Ribosomes The Endoplasmic Reticulum Synthesizes and Transports Proteins and Lipids

The ER attaches to the nuclear envelope > Rough ER is studded with ribosomes that synthesize proteins > Smooth ER lacks proteins and is where lipids are made

Transport vesicles carry proteins and lipids to Golgi apparatus for modification

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The Golgi Apparatus modifies and Golgi repackages proteins for distribution Apparatus (gray-green) • Golgi Body/Apparatus and transport – Package and process proteins & lipids vesicles – “Warehouse & finishing factory” – Receives vesicles from ER ‰ toward cytoplasm – Produces vesicles for finished products (proteins and lipids) • Vesicles are secreted from the via exocytosis

Pulse-labeled experiment - placed radioactive amino acids in the rough ER and observes the pathway of protein secretion Vesicles Vesicles—sacs containing enzymes • Interconnecting membrane system • • Nuclear membrane ‰ Rough ER ‰ Smooth ER ‰ Golgi apparatus ‰ – Lysosomes lysosomes/vacuoles ‰ plasma membrane • Intracellular digestion • Destroy bacteria in white blood cells • Breaks down damaged organelles – • Break down fatty acids & proteins • Detoxify alcohol & other toxic substances • Vacuoles—large vesicles for storing food & water – Only some eukaryotes

Lysosomes digest macromolecules and cell parts Peroxisomes break down long-chain fatty acids Lysosomes - membrane-bound vesicles produced by the Golgi apparatus • Peroxisomes - small, membrane-bound • Important in recycling cellular material and digesting worn-out organelles organelles resembling empty lysosomes • Tay Sachs disease – when a particular lysosomal enzyme is nonfunctional • Contain enzymes to digest excess fatty acids > Produces products used by mitochondria to make ATP • Produce cholesterol and phospholipids found in brain and heart tissue

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The Organelles of the Endomembrane The Organelles of the Endomembrane System System Work Together

Endomembrane System is a series of membranous organelles that work together and communicate via transport vesicles Includes: ER (rough & smooth) Transport Vesicles Golgi Apparatus Lysosomes

Vacuoles Vacuoles have varied functions in protists Various functions in protists and plants and plants • Central vacuole – found in plants, contains • Vacuoles – membranous sacs larger than • watery sap and maintains turgor pressure, vesicles and usually store substances • Storage (amino acids, sugars, ions, wastes) Examples: • toxic substances used in plant defense • trap and export waste • pH buffers • store various small molecules needed by plant • ‘protein bodied’ in seeds (needed for germination)

Cells Carry Out Eukaryotes (plants) Energy Transformations ûPlastids ° Chlorloplasts öPhotosynthesis (energy from light) All actively metabolizing cells öOnly in plant cells carry out energy ° Leucoplasts öStore starches, est.. transformation öSpecialized ° Like mitochondria, may be artifact of ancient symbiotic relationship between prokaryotes & eukaryotes

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Plant Cell Anatomy :

1. Chloroplasts • site of photosynthesis

2. Leucoplasts • site of energy storage

Chloroplasts capture solar energy and Leucoplasts are also type of produce carbohydrates

Chloroplasts - type of plastid, an Different types of Leucoplasts: bounded by a double membrane with a series of internal membranes separated by 1. Site for storage of starch (), a ground substance lipids (oleoplasts), proteins (proteinoplast) • Starch stored for energy by plants Some algae have 1, some plant cells have that do not actively do 100. photosynthesis year round Sight of photosynthesis 2. Site for synthesis of amino acids and some lipids

Mitochondria break down carbohydrates and eukaryotes produce ATP • Mitochondria – Forms ATP (energy) from Mitochondria have a double membrane carbohydrates (as do some bacteria) – Requires oxygen – Site of cellular respiration • Often called the powerhouse of the cell – Similar to bacteria: have because they produce most of the ATP their own DNA & ribosomes • Cells that have high energy requirements • May be artifact of ancient symbiotic relationship (e.g., muscle) have high concentration of between prokaryotes & eukaryotes mitochondria

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Mitochondrion structure Mitochondria in Muscle Tissue

Mitochondria also contain DNA Malfunctioning mitochondria can cause human diseases (mtDNA) About 16,000 base pairs • Inadequate energy production, cause Function of this DNA … ??? energy loss of organism

Perhaps contribute important genes for • DNA damage may causes disease mitochondrial specific proteins.

Bi-products of ATP formation can damage mtDNA • Maintains Cell Shape (Internal shape & organization) and Assists Movement • Protein filaments between nucleus & plasma membrane mtDNA mutations can be inherited • Can be permanent or temporary Mutations in mitochondrial DNA (mtDNA) have been linked to diseases: Ex: Parkinsons or Alzheimer patients have more mtDNA mutations

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Cytoskeleton The Cytoskeleton consists of Filaments ûMicrotubules and ° Keep organelles & cell structures in place or move ûMicrofilaments them Actin Filaments - long, thin flexible fibers in ° Thin filaments ° ° Help in cell division (contracts bundled or mesh-like networks ° Compose cilia & flagellae midsection) • Play a structure role in the plasma membrane ûIntermediate filaments ° Anchor membrane proteins ° Ropelike structure ° Help support cell shape • Creates pseudopods amoebas to crawl ° Reinforce cell shape ° Muscle contraction (actin ° Anchor some organelles filaments) ° More permanent than other Actin Filaments interact with motor cytoskeleton molecules ; proteins that attach, detach, and reattach causing movement

Intermediate Filaments - size between actin filaments and microtubules > Support nuclear envelope or plasma membrane and are in cell-to-cell junctions

Microtubules – made of globular protein tubulin > Radiate from and maintain cell shape and create tracks along which organelles move

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Movement The three types • Motor proteins move things within cells of protein • Flagella—long outer structures for movement components of – Usually only a few the cytoskeleton • Cilia—short outer structures for movement – Usually many • Pseudopod – “False foot”

Cilia and Flagella contain Microtubules • Structures outside of the plasma membrane Cilia and Flagella - whiplike structures of • Holds cells together in tissues cells • Protects & supports plasma membrane • Some microbes use them to move • Collagen • In our bodies: – Glycoproteins > cilia remove debris from respiratory tract – Strong fibers > move eggs along oviduct > move digest through the digestive tract

Eukaryote surface Cells have Many Specializations of Structure for their Particular Functions • Plasma (cell) membrane – Regulates movement of “stuff” in and out of cell • Red blood cells lack a nucleus allowing more room for molecules of hemoglobin, the – Phospholipid bilayer molecule that transports oxygen in the blood • Muscle cells are tubular and specialized to contract • Nerve cells have very long extensions that facilitate the transmission of impulses

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Eukaryote Surface • In Multicellular Organisms, – Strong, gives permanent Cells Join Together shape to cell – Bacteria, protists, fungi, plants – Not found in animals • Plasmodesmata – Junctions between plant cell walls – Circulation and communication between cells

Plant cells are joined by Plasmodesmata Plants have a primary cell wall of cellulose microfibrils and a middle lamella of pectin

• Channels, plasmodesma, connect adjacent cells allowing water and solutes through

Animals cells have junctions between Animal cells are joined by plasma membranes: three different types of • Anchoring Junctions prevent leakage junctions

• Tight Junctions seal in digestive juices

• Gap Junctions allow cells to communicate

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Eukaryote surface Eukaryotes (animals) • Animal Cell Junctions – Tight junctions Extracellular matrix • Tight seal, prevents • Centrioles—produce during leakage of fluids cell division. – Anchoring junctions • Rivets • Fasten cells together – Gap junctions • Channels, pores • Allow small molecules to travel between neighboring cells • Cell-to-cell communication • Nutrient & waste transfer

Summary Eukaryotic cells contain several types of organelles. Not all eukaryotic cells contain every type of organelle. Different organelles serve different functions. Cytoskeleton proteins together with other proteins and carbohydrates serve important roles in motility, transport, cell structure, and tissue integrity.

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