Cell Structure and Function Chapter 6 Mr. Scott

Studying Cells A number of different techniques have been/are used to study cells A number of different techniques have been/are used to study cells Light microscopyLight microscopy Electron microscopyElectron microscopy Cell fractionationCell fractionation

Cell Fractionation Used for organelles Used for organelles Take the cell apart and separateTake the cell apart and separate Based upon the mass of the different organellesBased upon the mass of the different organelles Used with other techniques to evaluate structuresUsed with other techniques to evaluate structures

Cell Theory The cell theory All living things are composed of cells Cells are the basic units of structure and function in living things New cells are produced from existing cells Cells The basic unit of life

Cell Types Prokaryotes and Eukaryotes Prokaryotes and Eukaryotes Characteristics 1 to 100 micrometers Cell (plasma) membrane Cytosol/cytoplasm DNA/chromosomes Ribosomes

Prokaryotic Prokaryotes Prokaryotes Cells that do not contain nuclei Usually smaller than eukaryotic cells Less complicated All bacteria cells are prokaryotic

Cell Types

Eukaryotic Cells Eukaryotes Eukaryotes Cells that do contain a nucleus Usually larger than prokaryotic cells More complex Multicellular or unicellular Plants, animals, fungi, and protists

Cell Organelles Cell Factory Cell Factory Organelles Little organs Cytoplasm The fluid between the cell membrane and the nucleus Organelles live in the cytoplasm

Cell Organelles

Nucleus – control center of the cell Nucleus – control center of the cell Most of the cell’s genetic information is stored here Chromatin – granular material you can see Chromosome – condensed chromatin Nuclear envelope - covers the nucleus Nucleolus – ribosome production

Cell Organelles

Ribosomes – protein synthesis Ribosomes – protein synthesis Make proteins Distributed throughout the cell Free ribosomes Bound ribosomes

Cell Organelles

Endomembrane System Different membranes of the cell make different structures Different membranes of the cell make different structures Nuclear envelopeNuclear envelope Endoplasmic reticulumEndoplasmic reticulum Golgi apparatusGolgi apparatus LysosomesLysosomes Vessicles/VacuolesVessicles/Vacuoles Plasma (cell) membranePlasma (cell) membrane

Cell Organelles Endoplasmic Reticulum – transports material through the cell and makes lipids Endoplasmic Reticulum – transports material through the cell and makes lipids Cisternae – membrane tubules and sacs Rough E.R. – protein synthesis and hormones Smooth E.R. – makes lipids, processes carbohydrates, and gets rid of waste, Ca ion storage

Cell Organelles

Golgi Apparatus – Packaging center of the cell Golgi Apparatus – Packaging center of the cell Receiving Sorting Packaging Manufacturing

Cell Organelles

Lysosomes – use enzymes to digest foreign material Lysosomes – use enzymes to digest foreign material Work best in acidic environment Digest macromolecules

Cell Organelles

Vacoules Vacoules Saclike structure that is used to store materials Plant cells have a big vacuole that just holds water

Cell Organelles

Energy Organelles Energy Organelles Mitochondrion – converts food to energy ATP – adenosine triphosphate Comes from ovum Chloroplast – helps make sugar from the sun Organelle DNA Chloroplasts and Mitochondria have their own DNA

Cell Organelles

Peroxisomes Peroxisomes Metabolic compartments Enzymes remove H ions – transfer to oxygen to make water Makes H 2 O 2

Cell Organelles Cytoskeleton give the cell structure and movement within Cytoskeleton give the cell structure and movement within Microtubules Microfilaments Intermediate filaments

3-2 Cell Organelles

Cell Organelles Cell Locomotion Parts Cell Locomotion Parts Microvilli – (present in some cells) small hair like projections Cilia – hairlike structures Flagella – tail Centrosomes/Centrioles

Cell Organelles

Cell Wall Cell Wall Rigid layer of protection outside of the cell membrane Present in plants, algae, fungi, and prokaryotes

Cell Organelles

Extracellular Matrix Composed of: Composed of: GlycoproteinsGlycoproteins Collagen Collagen Other carbohydrate containing moleculesOther carbohydrate containing molecules FibronectinFibronectin IntegrinsIntegrins

Cell Junctions 3 types 3 types Tight junctionsTight junctions DesmosomesDesmosomes GapGap