dmi 261 radiation biology and protection unit 6 the human cell cell biology review
DESCRIPTION
Cell’s Chemical CompositionTRANSCRIPT
DMI 261 DMI 261 Radiation Biology Radiation Biology andandProtectionProtection
Unit 6Unit 6The Human CellThe Human Cell
Cell Biology ReviewCell Biology Review
Principle Cell Principle Cell MoleculesMolecules WaterWater 80%80% ProteinsProteins 15%15% LipidsLipids 2% 2% CarbohydratesCarbohydrates 1% 1% Nucleic AcidsNucleic Acids 1% 1%
Cell’s Chemical Cell’s Chemical CompositionComposition
Nucleic AcidsNucleic Acids RNARNA DNA DNA
– Double helixDouble helix– Sugar-phosphate Sugar-phosphate
chains chains – Nitrogenous Nitrogenous
basesbases
Nitrogenous BasesNitrogenous Bases Purines – Adenine and GuaninePurines – Adenine and Guanine Pyrimidines – Thymine and Pyrimidines – Thymine and
CytosineCytosine
– adenine only bonds with guanineadenine only bonds with guanine– thymine only bonds with cytosinethymine only bonds with cytosine– Hydrogen bondsHydrogen bonds hold the bases hold the bases
togethertogether
Cell StructureCell Structure
Cell StructureCell Structure Cell membraneCell membrane
– BarricadeBarricade– Controls passage of water and other Controls passage of water and other
materials in and out of the cell.materials in and out of the cell.
CytoplasmCytoplasm– Protoplasm that exists outside of the Protoplasm that exists outside of the
nucleus.nucleus.
OrganellesOrganelles Endoplasmic Endoplasmic
ReticulumReticulum– Transportation Transportation
system for food system for food and communication and communication with outside with outside environmentenvironment
– Rough have Rough have ribosomesribosomes
– Smooth do notSmooth do not
OrganellesOrganelles Golgi ApparatusGolgi Apparatus
– Concentrates, Concentrates, packages and packages and transports transports enzymes and enzymes and hormones hormones through the cell through the cell membranemembrane
OrganellesOrganelles MitochondriaMitochondria
– Power house of Power house of the cellthe cell
– Produces energy Produces energy for cell activity by for cell activity by breaking down breaking down nutrientsnutrients
OrganellesOrganelles LysosomesLysosomes
– Garbage disposalsGarbage disposals– Break down large Break down large
molecules that molecules that enter the cellenter the cell
– Contain digestive Contain digestive enzymes that can enzymes that can destroy a cell if its destroy a cell if its membrane membrane rupturesruptures
OrganellesOrganelles RibosomesRibosomes
– Protein factoriesProtein factories– Make proteins as Make proteins as
instructed by instructed by mRNAmRNA
OrganellesOrganelles CentrosomesCentrosomes
– Contain centrioles Contain centrioles which help form which help form mitotic spindlesmitotic spindles
OrganellesOrganelles NulceusNulceus
– Heart of the cellHeart of the cell– Contains DNA, Contains DNA,
nucleolus (RNA), nucleolus (RNA), controls cell controls cell division and all division and all other cellular other cellular activityactivity
Cell DivisionCell Division Multiplication process by which one Multiplication process by which one
cell forms two or more cellscell forms two or more cells
MitosisMitosis Process by which Process by which
somaticsomatic cells cells dividedivide
InterphaseInterphase Period of cell Period of cell
growth that growth that occurs before occurs before mitosis.mitosis.
DNA replication DNA replication occurs here.occurs here.
Cell CycleCell CycleG1, S, and G2 = parts of interphase that lead up to G1, S, and G2 = parts of interphase that lead up to
mitosismitosis
Stages of MitosisStages of Mitosis
MeiosisMeiosis Method by which germ cells Method by which germ cells
(reproductive) divide in sexually (reproductive) divide in sexually reproducing plants and animals.reproducing plants and animals.
Only ½ of the chromosomes are Only ½ of the chromosomes are produced.produced.
Process of Process of reduction divisionreduction division where the cell divides twice but where the cell divides twice but DNA is replicated only once.DNA is replicated only once.
MeiosisMeiosis
END REVIEWEND REVIEW