Transcript Power Point - Brands Delmar

Chapter 3
Cells
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Cells
• The cell is the basic unit of structure and
function of all living things
• Cell or plasma membrane
• Nucleus
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Nucleus
• Most important organelle within the cell
• Function
– Control the activities of the cell and facilitate cell division
• DNA and chromatin
• Chromosomes
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Functions of Organelles
• Nuclear membrane or nuclear envelope
– Regulates transport of substances into and out of the cell
• Nucleoplasm
– A clear, semi-liquid medium that fills the spaces around the
chromatin and the nucleoli
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Functions of Organelles
• Nucleolus
– Reservoir for RNA
• Ribosomes
– Serves at site for protein synthesis
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Functions of Organelles
• Cytoplasm
– Provides an organized watery environment, in which life
functions take place by the activities of the organelles contained
in the cytoplasm
• Centrosome
– Contains two centrioles that are functional during animal cell
division
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Functions of Organelles
• Endoplasmic reticulum
– Provides passage through which transport of substances occurs
in cytoplasm
• Mitochondria
– Serves as sites of cellular respiration and energy production;
stores ATP
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Functions of Organelles
• Golgi apparatus
– Manufactures carbohydrates and packages secretions for
discharge from the cell
• Lysosomes
– Serve as center for cellular digestion
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Functions of Organelles
• Perioxisomes
– Enzymes oxidize cell substances
• Cytoskeleton
– Forms internal framework
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Functions of Organelles
• Pinocytic vesicles
– Method by which large molecules can enter the cell
• Cilia and flagella
– Create movement
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Cellular Metabolism
• Chemical reactions occur within the cells
• Energy supplied by ATP
• ATP created from CHO, proteins, and fats
we eat
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Cell Division
• Meiosis
– Involves reproduction
• Mitosis
– Involves growth and maintenance of cells
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Meiosis
• Process of cell division of the sex cell or
gamete
• Ovum and spermatozoa reduce chromosomes
from 46 to 23
• Fertilization
• Zygote is formed from two sex cells to
obtain full set of 46 chromosomes
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Mitosis
• Cell division
– Division of the nucleus
– Division of the cytoplasm
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Mitosis Stages
• Phase I
– Interphase (resting stage)
• Phase II
– Prophase
• Phase III
– Metaphase
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Mitosis Stages
• Phase IV
– Anaphase
• Phase V
– Telophase
• Cycle back to interphase
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Cell Death
• Necrosis
• Apoptosis
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Stem Cells
• Embryonic stem cells
• Adult stem cells
• Umbilical cord blood stem cells
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Protein Synthesis
• Cells produce proteins
• DNA
• RNA
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Movement of Materials
Across Cell Membranes
• Passive transport
– Do not require an energy source
• Active transport
– Require an energy source
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Passive Transport
• Diffusion
• Osmosis
• Filtration
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Active Transport
• Phagocytosis
• Pinocytosis
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Specialization
• Nerve cells
– Specialize in response
• Red blood cells
– Specialize in oxygen transport
• May lose some functions, such as
reproduction
• Interdependence among cells
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Animation – Anatomy
of a Typical Cell
Click Here to play
Typical Cell animation
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Aging
• Aging is a phase of normal development
• Older person may have 30% fewer cells
• Cells may change in ability to perform
specialized tasks
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Aging
• Physiologic changes are universal and
progressive
• Aging is not a disease
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Disorders of Cell Structure
• Atrophy
• Hypertrophy
• Hyperplasia
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Disorders of Cell Structure
• Metaplasia
• Dysplasia
• Neoplasia
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Tumor
• When cell division does not occur in the
usual pattern
• Also called neoplasms
• Benign tumors
• Malignant tumors
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