The Cell Structure and Function

The Discovery of the cell ______________________ ______________________ –Used a microscope to identify small pieces of cork which he called “CELLS” ______________________ ______________________ –Concludes that plants are made of cells ______________________ ______________________ –Concludes that all animals are made up of cells ______________________ ______________________ –All cells come from existing cells

Cell Theory

Transmission Electron Microscope Electron microscopes show details not visible with light microscopes. Electron microscopes show details not visible with light microscopes. Uses electron beams to focus and magnify an image. Uses electron beams to focus and magnify an image. Higher magnification Higher magnification

Microscopes Light microscopes 1000x Light microscopes 1000x –Produce magnified images by focusing visible light Electron microscopes Electron microscopes –Produce magnified images by focusing beams of electrons. (can’t use living specimens) –TEM – –SEM –

Inside the cell 2 types of cells 2 types of cells –___________  You  Found on Earth after prokaryotes

Types of Cells (General) Prokaryotes Prokaryotes –____________________________ –“primitive cells” –Ex. Bacteria Eukaryotes Eukaryotes –Have a _____________ and usually are bigger and have more organelles than a prokaryotic cell does. –Ex. Plant and animal cells

Eukaryotes Like Chicago Like Chicago –Big city –Lost of stuff –Everything you need to live

Prokaryotes Like ______ Like ______ –Not too big –Simple –Small city

Eukaryotes vs. Prokaryotes Eukaryotes Eukaryotes Every living organism (except bacteria) Every living organism (except bacteria) Cell membrane Cell membrane Cytoplasm Cytoplasm Ribosomes (make protein) Ribosomes (make protein) PROKARYOTES PROKARYOTES Cell membrane Cell membrane Cytoplasm Cytoplasm Ribosomes Ribosomes No organelles No organelles

Nucleus Surrounded by a double layered membrane called the nuclear envelope. Surrounded by a double layered membrane called the nuclear envelope. Contains DNA Contains DNA _________________ _________________ –Dense molecules of DNA & protein ___________________ ___________________ –Chromatin stands that coil and condense. –“blueprints” that control cellular activity. ______________________ ______________________ –Site where ribosomes are built

Cytoplasm __________________________________ __________________________________ __________________________________ __________________________________ Made up of cytosol & organelles Made up of cytosol & organelles Organelles Organelles –Structures that work like miniature organs, carrying out specific functions in the cell.

Organelle Analogies If the cell was a factory If the cell was a factory –_______________  The energy supply; power supply –_______________  Solar panels –_______________  The control center / boss’ office –_______________  Network or assembly line for proteins

–_____________  Mail room – packaging and sorting of materials –_____________  The janitor –_____________  Specific janitor –_____________________  Pipes that come off the factory –_____________________  Security desk –______________  Carpenters that build proteins

Plant Cells Plants have a cell wall unlike animal cells made up of a strong polysaccharide cellulose. Plants have a cell wall unlike animal cells made up of a strong polysaccharide cellulose. Have chloroplasts Have chloroplasts Chromoplasts & carotanoids – other colors Chromoplasts & carotanoids – other colors

Cell Shape The shape of the cell usually depends on its function The shape of the cell usually depends on its function –Ex. Nerve cells – long & stringy  Plants – rigid Cytoskeleton Cytoskeleton –Made up of microtubules & microfilaments

Microtubules Maintain the shape of the cell & serve as tracks for organelles to move upon Maintain the shape of the cell & serve as tracks for organelles to move upon

Microfilaments Can contract Can contract Found in high concentration in muscle cells Found in high concentration in muscle cells

Go to Section: Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Mitochondrion Section 7-2 Figure 7-11 Cytoskeleton

Plant vs. Animal Cell PLANT PLANT ___________ ___________ Cell membrane Cell membrane Large vacuoles Large vacuoles Animal Animal No chloroplast No chloroplast ____________ ____________ Cell membrane Cell membrane ____________ ____________

Go to Section: ProkaryotesEukaryotes Cell membrane Contain DNA Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Animal CellsPlant Cells Centrioles Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Cell Wall Chloroplasts Section 7-2 Venn Diagrams

Go to Section: Plant Cell Nuclear envelope Ribosome (attached) Ribosome (free) Smooth endoplasmic reticulum Nucleus Rough endoplasmic reticulum Nucleolus Golgi apparatus Mitochondrion Cell wall Cell Membrane Chloroplast Vacuole Section 7-2 Figure 7-5 Plant and Animal Cells

Go to Section: Animal Cell Centrioles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Golgi apparatus Smooth endoplasmic reticulum Mitochondrion Cell Membrane Ribosome (free) Ribosome (attached) Section 7-2 Figure 7-5 Plant and Animal Cells

Parts of the cell Cell Membrane (plasma membrane) Cell Membrane (plasma membrane) –A thin layer of lipid and protein that separates the cell’s contents from the world around it. –Phospholipids are polar  The two ends are opposites of each other.

Crossing the membrane To stay alive, a cell must exchange materials such as food & wastes with its environment To stay alive, a cell must exchange materials such as food & wastes with its environment –To do this it must pass material through the plasma membrane

Phosphate head is hydrophilic Phosphate head is hydrophilic Tail is hydrophobic Tail is hydrophobic Cell membrane consists of 2 phospholipid layers called a bilayer Cell membrane consists of 2 phospholipid layers called a bilayer

Go to Section: Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains Section 7-3 Figure 7-12 The Structure of the Cell Membrane

Semipermeable membrane __________________________________ __________________________________ __________________________________ __________________________________ __________________________________ __________________________________ Small molecules, such as water, can go in and out freely, but large molecules cannot. Small molecules, such as water, can go in and out freely, but large molecules cannot. Ions cannot pass through either Ions cannot pass through either

Passive Transport Transport of substances that __________________________________ Transport of substances that __________________________________ 3 types 3 types

Diffusion The net movement of molecules from an area of high concentration to an area of low concentration. The net movement of molecules from an area of high concentration to an area of low concentration. Speed of diffusion Speed of diffusion –Depends on temperature and size of molecule

Concentration Gradient The difference between the concentration of a particular molecule in an area and the concentration in an adjacent area. The difference between the concentration of a particular molecule in an area and the concentration in an adjacent area. Diffusion always occurs down a concentration gradient, from area of greatest concentration to areas of lesser concentration Diffusion always occurs down a concentration gradient, from area of greatest concentration to areas of lesser concentration

Osmosis The movement of __________ through a semipermeable membrane from areas of high concentration to areas of low concentration. The movement of __________ through a semipermeable membrane from areas of high concentration to areas of low concentration. Refers to the concentration and movement of ___________ Refers to the concentration and movement of ___________

Hypertonic solutions The concentration of solutes outside the cell is greater than the concentration of solutes inside the cell. The concentration of solutes outside the cell is greater than the concentration of solutes inside the cell. In hypertonic solutions, _________________________________ In hypertonic solutions, _________________________________

Video 2 Click the image to play the video segment. Click the image to play the video segment. Video 2 Osmosis

Hypotonic solutions The concentration of solutes outside the cell is lower than the concentration inside the cell. The concentration of solutes outside the cell is lower than the concentration inside the cell. In hypotonic solutions, __________________ In hypotonic solutions, __________________

Isotonic solutions The concentration of solutes inside the cell equals the concentration of solutes outside the cell. The concentration of solutes inside the cell equals the concentration of solutes outside the cell.

Video 3 Click the image to play the video segment. Click the image to play the video segment. Video 3 Passive Transport

Facilitated Diffusion A type of passive transport that uses carrier proteins to help pass large molecules through membrane. A type of passive transport that uses carrier proteins to help pass large molecules through membrane. EX. EX.

Video 4 Click the image to play the video segment. Click the image to play the video segment. Video 4 Active Transport

__________________________________ __________________________________. __________________________________ __________________________________. Move solutes __________ the concentration gradient Move solutes __________ the concentration gradient Ex. Na/K pump Ex. Na/K pump – EX. plant roots absorbing nutrients in the soil.

Go to Section: Molecule to be carried Molecule being carried Energy Section 7-3 Figure 7-19 Active Transport

Exocytosis and endocytosis – transport of large molecules ___________________ ___________________ –The cell secretes marcomolecules by the fusion of vesicles with the plasma membrane ___________________ ___________________ –The cell takes in macromolecules or substances from the plasma membrane –3 types  1. phagocytosis – “cellular eating”  2. pinocytosis – “cellular drinking”  3. receptor – mediated endocytosis –Extracellular substances bind to receptors called ligands and the substances are then brought into the cell

Video 5 Click the image to play the video segment. Click the image to play the video segment. Video 5 Endocytosis and Exocytosis

Multicellular advantages Cells throughout an organism can develop in different ways to perform different ways to perform different tasks Cells throughout an organism can develop in different ways to perform different ways to perform different tasks ___________________ ___________________ –Different cells with different functions –Ex. Blood cells, nerve cells, muscle cells

Levels of Organization _______________ _______________ –A group of similar cells that perform a particular function –Ex. Smooth muscle tissue _______________ _______________ –Many groups of tissues that work together. –Ex. Stomach _______________ _______________ –A group of organs that work together to perform a specific function. –Ex. Digestive system