cell structure and function
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Cell Structure and Function. Scientists responsible for the tools and foundations of cell biology:. Robert Hooke 1665 term “cell” observed cork. Scientists responsible for the tools and foundations of cell biology:. Anton van Leeuwenhoek 1674 - PowerPoint PPT PresentationTRANSCRIPT
Cell Structure and Function
Scientists responsible for the tools and foundations of cell biology:
Robert Hooke1665term “cell”observed cork
Scientists responsible for the tools and foundations of cell biology:
Anton van Leeuwenhoek
1674used high quality lenses to
improve microscopepond water - animalculesrecognized cells as basic
unit of life
Scientists responsible for the tools and foundations of cell biology:
Robert Brown1830’s discovered the cell’s nucleusnucleus directs cell division
Scientists responsible for the tools and foundations of cell biology:
Matthias Schleiden1838plants composed of cells
Scientists responsible for the tools and foundations of cell biology:
Theodor Schwann1839animals composed of cells
Scientists responsible for the tools and foundations of cell biology:
Rudolf Virchow1855new cells arise from the
division of preexisting cells
Cell TheoryThe work of these scientists provided information significant to the development of the cell theory
All living things are composed of cells Cells are alike in chemical composition and structure Cells are the smallest working unit of living things All cells arise from other cells
All living organisms are alike because they are composed of cells… by studying the composition and chemistry of the cell, we understand the chemistry and composition of all kinds of life forms
Breaking it down…… introduction to biochemistry
What is biochemistry???
Bio chemistryThe study of matter and the changes in matter
Pertaining to life
ProteinsCarbohydrates Lipids
Nucleic Acids
Macromolecules
Polymer: Very large molecule made from individual pieces
MonomerAKA: Subunit
• Hydrolysis: Breaks apart the polymer into monomers
• Water needed to break the bond
• Dehydration Synthesis: AKA: Polymerization
• Links the monomers together to form the polymer
• Produces water
What do monomers look like?• Hydrocarbon: Molecule containing Hydrogen and Carbon
Ethane
Ethene
EthyneUnsaturated
Saturated
Molecular Structure
CHAIN BRANCH RING
Substituted Hydrocarbon
• Hydroxyl -OH• Add –ol suffix to name• Creates an alcohol• Used to disinfect or as a
fuel
Methanol
Methane
• Carboxyl Group -COOH• Creates a carboxylic
acid or organic acid• Found in citrus fruits,
vinegar (ethanoic acid)
Methane
Methanoic Acid
• Amine -NH2• Includes novocaine,
painkiller
Methylamine
Methane
Carbohydrates
Proteins
Lipids
Nucleic Acids
Group Project- Make a Biological Molecule
• Build a biological molecule to hang from the ceiling.
• Include all major structures. • Sketch out model before building. • You will have 20 minutes in class today and
tomorrow to collaborate and 30 minutes to build on Friday.
• Be creative!!!
Enzyme Salad Lab• Test Tubes Containing the following
– 1. Frozen + Gelatin– 2. Fresh + Gelatin– 3. Canned + Gelatin– 4. Gelatin
• Place the test tubes in an ice bath. Once tube 4 has gelled, record observations in the table.
Observations Before Ice Bath
Observations After Ice Bath
Frozen + GelatinFresh + GelatinCanned + GelatinGelatin
Discussion Questions1. Why did test tube #4 contain only gelatin?
2. What could account for the different results in the tubes?
3. How could the canning process change bromelin?
4. What could you do to fresh pineapple that would allow the salad to gel?
Catalyst
Enzymes
Organic Molecules that compose “life’s building blocks”Organic Group Polymer Monomer Functions of polymers
in the cell
Carbohydrates Sugars EnergyStorage of energyBuilding materials
Proteins Amino Acids EnzymesBuilding blocksMessengersTransport etc…all the life’s work
Lipids Long chains of carbon and hydrogen
Cell membrane building blocksEnergy storageChemical messengers
Nucleic Acids Nucleotides Hold recipes for proteins “Code of Life”
Enzyme activity (video)
A. Enzymes put molecules together……SYNTHESIS.
B. Enzymes take molecules apart…… DIGESTION.
C. Enzymes control chemical reactions…….LIFE.D. Enzymes make chemical reactions require less energy.
Enzyme A Enzyme B
Substrate
Lock and Key Theory for Enzyme Action
Cells and cell types
Prokaryotic vs. Eukaryotic Cells
• No Nucleus• Small and simple• No organelles• Sticky capsule• Contains cell wall
(peptidoglycan)• First cells• Live in a wide variety of
environments• Include bacteria
• Nucleus• Organelles• Unicellular or multicellular• Cytoskeleton• Some have cilia• Include all cells but
bacteria
Single Cell• Monera• Prokaryotic – lacking a
nucleus and any organelles • Reproduce by binary fission –
splitting into two• Ex. Bacteria • Protista
• Eukaryotic – Nucleus present• Have organelles that carry
out specific functions• Ex. Amoeba, paramecium,
euglena
Multi Cell
• Fungi• Eukaryotic – Nucleus present• Cell Wall composed of chitin• Saprophytic (food comes from dead
organic material)• Individual cells are not completely separate
from neighboring cells• Ex. Bread mold, mushrooms, Athlete’s foot
• Animal• Eukaryotic – Nucleus present• Heterotrophic – food comes
from organic material• No cell wall or chloroplast• Do have centrioles
• Plants• Eukaryotic – Nucleus present• Cell Wall composed of cellulose• Autotrophic – can produce their
own food• Chloroplasts, large vacuoles
Quick Quiz!! If you found a new organism and it was multicellular, did not contain chloroplasts, but did have cell walls, which kingdom would you expect it to belong
to? A. MoneraB. ProtistaC. FungiD. PlantaeE. Animalia
How did the first cells form?Oparin – Haldane Hypothesis (1920’s)
Prebiotic Soup:
Methane (CH4)Hydrogen gas (H2)Ammonia gas (NH3)Water vapor (H2O)Very Little Oxygen!!
Earth’s Conditions:volcanic eruptionsUV radiationlightningmeteor bombardment
Idea based on the behavior of energy and molecules found in all living things
UV radiation synthesized the first organic compounds from inorganic precursors
Testing the HypothesisStanley Miller (1953)
Set up experiments using O-H hypothesisProduced simple amino acids
1 week!!!
Amino Acids- building blocks for all life forms, protein components
Molecules + Energy = Larger molecules and chemical compounds
Results = Theory of How Earth’s Life Began
Evidence:
20 amino acidscommon sugarslipidsDNA and RNAATP
Molecules of
LIFE
These have all been recreated in the laboratory. All the steps to making simple cells have been recreated under lab conditions!!
Quick Quiz!! What organelles are made up of lipids?
1. Cell membrane2. Nuclear membrane3. Endoplasmic
reticulum4. Golgi Bodies5. All of the above
Cell m
embra
ne
Nuclear
membran
e
Endoplas
mic ret
iculum
Golgi B
odies
All of th
e above
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Conclusion = Theory of How Earth’s Life Began
1.) The Earth consisted of prebiotic soup from which small organic compounds were made
2.) Small molecules were joined to make larger molecules
3.) Molecules organized into droplets with different Characteristics than the molecules alone.
4.) Origin of heredity: formation of DNA allows primitive cells to reproduce themselves and pass on info.
Endosymbiont Hypothesis
Lynn Margulis (1970) proposed an evolutionary explanation for eukaryotic cells
…Eukaryotic cell is the result of prokaryotic cells living enclosed in one cell Symbiotic:mutually benefiting from the relationship
Prokaryotes vs. Eukaryotes
Prokaryotic CellsNo nucleusSimple cellsFunction simplyEx. – BacteriaPrecursors to eukaryotes
Eukaryotic CellsNucleus presentComplex and organizedcomplex and specialized
functionsEx. – all body cells, plant cells,
fungi, etc.Evolutionarily advanced over
prokaryotic cells
Cell MembraneFunction:
-Separates the cell from its surroundings-Protects the cell
contents- Determines what raw
materials will enter*- Releases waste
products produced inside of cell*
*Transport Mechanisms
Cell MembranePhospholipid Bilayer
…flexible barrier allowing only lipid soluble substances
into the cell…fluid mosaic model =
individual phospholipids can move around within the membraneProteins
…pump for specific substances into/out of cells
…open channels for certain materials
Carbohydrates…membrane stabilizers (cholesterol)…chemical identification of the cell
Nucleus
Functions:- control center, cell activities are primarily directed from the nucleus- Contains the DNA and proteins = CHROMATIN- Chromatin condenses during reproduction to form CHROMOSOMES
Quick Quiz!! The majority of chromosomes are made up of what kinds of molecules?
A. CarbohydratesB. LipidsC. ProteinsD. Nucleic Acids
Nucleus
Membrane boundporous membrane
Nucleolus
Dark staining structure within the nucleusContains r-RNA, makes ribosomes
Cell Fluids
Nucleoplasm:Inside of the nucleus
Plasm = fluidCyto = cell
Cytoplasm: Outside of the nucleus
Cytoplasm
Organelles in the cytoplasm of all eukaryotic cells:RibosomesEndoplasmic ReticulumGolgi ApparatusLysosomesCytoskeletonVacuolesMitochondria
Organelles in some eukaryotic cells:CholoroplastsCell WallFlagellaCiliaCentrioles
Ribosomes
Tiny structure where proteins are assembled from amino acids
Endoplasmic ReticulumNetwork of membranes dividing cytoplasm and directing the flow of material through the cell
Rough – ribosomes attached, rough appearanceSmooth – no ribosomes, smooth appearance
Quick Quiz!! Because ER is made from membranes, what type of organic macromolecule would you expect it to be constructed
from?
A. CarbohydratesB. LipidsC. ProteinsD. Nucleic Acids
Carbohy
drates
Lipids
Protei
ns
Nucleic
Acids
18% 18%18%
47%
Golgi ApparatusTightly grouped membranous structure where proteins are condensed, collected, and packaged for storage or shipment out of the cell
Produces lysosomes, vesicles, and vacuoles
Lysosome, Vacuoles, and Vesicles:
Lysosome: sac-like structure containing enzymes for cellular breakdown; recycling plant
Vacuoles and Vesicles: - store carbs, water, salts,
fats, etc.-Vacuoles may be larger-In plants, vacuole provides support- Vacuoles stay in cells- Vesicles bring things
into/out of cells
Quick Quiz!! After a protein has just been produced, where is it most likely to go?
A. A ribosomeB. The ERC. A vesicleD. The Golgi
Apparatus
A riboso
me
The ER
A vesic
le
The Golg
i Appara
tus
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Cytoskeleton
Microtubule and microfilament network that provides a frameworkMovement of proteins inside cellMovement of the cell
Mitochondrion
Contain their own DNATakes chemical fuel (glucose) and converts it into small useable packages (ATP)
Organelles in some eukaryotic cells but not all…
Chloroplasts
Contain their own DNALight absorbing structure that package ENERGY in glucose
Cell Walls
Structure that surrounds cell membraneProvides support and rigidity to cellsIn plants, composed of celluloseIn fungi, composed of chiten
Flagella
Tail-like structures used for locomotion
Cilia
Short, hair-like structures on the surface of the cellUsed for locomotion and to move materials near cell
Centrioles
Only in animal cellsUsed in cell division
Quick Quiz!! In addition to centrioles, what else is made of microtubles?
A. CytoskeletonB. MitochondriaC. Cell wallsD. RibosomesE. Endoplasmic
reticulum
Cytosk
eleton
Mito
chond
ria
Cell w
alls
Ribosomes
Endoplas
mic ret
iculum
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