Download HOC 1 - 8 The Cell

Health Occupations
The Cell
Definitions
Anatomy
Study of form & structure of organism
Physiology
Study of processes of living organisms, why &
how they work
Pathophysiology
Study of how disease occurs & responses of
living organisms to disease processes
Protoplasm
Basic substance of life
 Makes up all living things
 Carbon, oxygen, hydrogen, sulfur,
nitrogen, phosphorus
 Unique combo we call life
 Forms the basic unit of structure in all
living things – the cell
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The Cell

Microscopic
 Carries on all functions of life
 Building block of the body
 Functions
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Takes in food and oxygen
Produces heat & energy
Moves & adapts to the environment
Eliminates wastes
Performs special functions
Reproduces to create new, identical cells
Cell Parts
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Cell Membrane –
– Outer protective covering
– Semi permeable
• Allows certain substances in & out
• Prevents other substances from leaving or
entering
Cell Membrane
Cell Parts
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Cytoplasm
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Jelly like fluid inside cell that surrounds cell parts
Water, proteins, lipids, CHO, minerals, salts
Site for all chemical reactions in cell
Contains organelles
• Cell structures that help cell function
• nucleus, mitochrondria, ribosomes, liposomes,
centrioles, Golgi apparatus, endoplasmic reticulum
Cell Membrane
Cytoplasm
Cell Parts - Organelles
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Nucleus
– Brains of the cell
– Controls cell activities
– Directs reproduction
Nucleus
Cell Membrane
Cytoplasm
Cell Parts - Organelles
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Nucleolus
– Inside nucleus
– Important for reproduction
– Manufactures ribosomes
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RNA – ribonucleic acid & protein
Move from nucleus to cytoplams
Aids in protein synthesis (production)
Can exist freely or as attached to endoplasmic
reticulum
Ribosomes
Nucleolus
Nucleus
Cell Membrane
Cytoplasm
Cell Parts - Organelles
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Chromatin
– Inside nucleus
– Make up of DNA
• Deoxynucleic acid & protein
– During reproduction
• Chromatin condenses & forms chromosomes
• Human has 46 or 23 pairs
• Chromosomes
– 100,000 genes with inherited characteristics
– Gene
» Specific & unique code of about 1,000 DNA pairs that
carry coding for exact cell duplication
» Can be used for identification because each sequence
is unique
Ribosomes
Nucleolus
Chromatin
Nucleus
Cell Membrane
Cytoplasm
Cell Parts - Organelles
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Centrosome
– Located in cytoplasm near nucleus
– Contains 2 centrioles
– During mitosis (cell division), centrioles
separate
– Cytoplasmic spindle fibers form between
centrioles & attach to chromosomes
• Creates an even division of chromosomes in
the 2 new cells
Ribosomes
Nucleolus
Chromatin
Nucleus
Centrosome
Cell Membrane
Cytoplasm
Cell Parts – Organelles
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Mitochondria
– Rod-shaped
– Furnaces or power houses of cells
– Break down CHO, proteins, fats
– Produce ATP
• Adenosine triphosphate
• Cell’s major energy source
Ribosomes
Nucleolus
Chromatin
Nucleus
Centrosome
Mitochondria
Cell Membrane
Cytoplasm
Cell Parts - Organelles
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Golgi Apparatus
– Stack of membrane layers
– Produces, stores, packages secretions for
discharge from cell
– Salivary, gastric, pancreatic cells have
many golgi apparatus
Golgi apparatus
Nucleolus
Chromatin
Nucleus
Centrosome
Ribosomes
Mitochondria
Cell Membrane
Cytoplasm
Cell Parts - Organelles
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Endoplasmic reticulum (ER)
– Fine network of tubular structures
– Allows for transport of materials in & out of
nucleus
– Aids in synthesis & storage of proteins
– Rough Endoplasmic reticulum
• Has ribosomes, sites for protein production
– Smooth Endoplasmic reticulum
• No ribosomes, not present in every cell
• Assists with cholesterol synthesis, fat metabolism, & drug
detoxification
Golgi apparatus
Nucleolus
Chromatin
Nucleus
Centrosome
Rough ER
Ribosomes
Mitochondria
Cell Membrane
Cytoplasm
Smooth ER
Cell Parts - Organelles
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Lysosomes
– Oval or round bodies in cytoplasm
– Contain digestive enzymes that digest and
destroy
• Old cells
• Bacteria
• Foreign materials
– Important function of immune system
Golgi apparatus
Nucleolus
Chromatin
Nucleus
Centrosome
Lysosome
Rough ER
Ribosomes
Mitochondria
Cell Membrane
Cytoplasm
Smooth ER
Cell Parts – Organelles
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Pinocytic vessels
– Pocket like folds in cell membrane
– Allow large molecules like fats & proteins
to enter cell
– When molecules are inside, folds close to
form vacuoles or bubbles in cytoplasm
Golgi apparatus
Nucleolus
Chromatin
Nucleus
Centrosome
Lysosome
Rough ER
Ribosomes
Mitochondria
Pinocytic vessel
Cell Membrane
Cytoplasm
Smooth ER
Cell Parts - Organelles
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Vacuole
– Closet or storage place of cell
– May be empty or full
– Looks like bubble in cytoplasm
Golgi apparatus
Nucleolus
Chromatin
Nucleus
Centrosome
Lysosome
Rough ER
Ribosomes
Vacuole
Mitochondria
Pinocytic vessel
Cell Membrane
Cytoplasm
Smooth ER
Homeostasis
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Tendency of a cell to maintain a state of
balance
 Molecules pass in & out of cell to do this
 Cells constantly adjust these to maintain
balance
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Fluids
Temperature
Oxygen
Electrolytes
Nutrients
Electrolytes
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Compounds made of charged particles or
ions
Conduct electrical current in water or
cytoplasm
+ charge = cation (acid) Na++, K+, Mg++, H+
- charge = anion (base) HCO3, HPO4, C,
SO4)
pH measures how much acid/base is present
– Each tissue has own normal pH
– If pH is not maintained, cell doesn’t function right
Cellular reproduction
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Mitosis
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Most cells
Divides into 2 identical cells
Asexual
Continuous reproduction
• Skin, blood, intestines
– Every few years
• Muscle
– Never
• Spinal cord, nervous cells, brain cells
Mitosis
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DNA molecules duplicate themselve
Centrioles separate & a spindle forms
between them
Duplicated chromosomes line up along
center of spindle
Chromosomes separate
Two nuclei form as cell separates
Each new cell has the full number of
chromosomes
Meiosis
Process by which sex cells divide
 Uses 2 separate cell divisions to
produce 4 new cells
 Ova – female cells
 Spermatozoa – male cells
 Chromosome number decreases to 23
(1/2 of mitosis) before division
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Meiosis
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When ova & sperm join, form a zygote (new
cell) with 46 chromosomes (23 from ova & 23
from sperm)
 After zygote forms, rapid mitosis occurs
 4-5 days, becomes blastocyst which contains
embryonic stem cells
– Stem cells have ability to transform into any
specialized cell & perform functions
– Controversy – can stem cells cure diseases like
DM, Parkinson’s disease, osteoporosis, arthritis,
heart disease?
Heredity

Passing on of genetic information that
determines individual characteristics
 Determines physical appearance, blood type,
gender
 Genes
– Contain heredity info in cell
– Made up of DNA forming chromosomes
– 50-100,000 genes on each chromosome
determining general human & individual traits
– Dominant gene – characteristic appears when
only 1 gene is inherited
– Recessive gene – trait only appears when gene is
present on both chromosomes
Abnormal genes

Cause many inherited, hereditary, or genetic
disorders
 Described as CONGENITAL or CONDITION
rather than contagious or disease
 Some disorders affect only 1 body part,
others affect entire systems
 Disorders include – clubfoot, cleft lip/palate,
cystic fibrosis, Down’s syndrome,
Huntington’s chorea, Klinefelter’s syndrome,
Neural tube defect, Neurofibromatosis, PKU,
Sickle cell anemia, Tay-Sachs disease