Transcript Animal Cell - TeacherWeb

Cell Structures, Functions and
Transport
Cell Basics
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basic unit of structure and function in living
things
complex structures
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most specialized to perform certain functions
coordinated functions critical for survival
composed of four basic chemicals
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C, O, H, N
plus traces of Fe, Na, K, Ca
60% water
Functions of Cell
Structure defines function.
1.
2.
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basic unit of life
protection and support
movement
communication
cell metabolism and energy release
inheritance
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3 main regions
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2.
3.
nucleus
cytoplasm with organelles
nuclear membrane
Figure 7-5 Plant and Animal Cells
Section 7-2
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Animal Cell
Animal Cell
Nucleus
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the control center
holds the DNA – instruction for building
proteins necessary for cell reproduction
nucleus
3 regions of nucleus
1.
Nuclear membrane – double membrane
with “moat” in between
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2.
selectively permeable
encloses nucleoplasm
Outer and inner membranes form pores.
Nucleolus: where ribosomes are
assembled
chromatin – fibers that form dense, rodlike structures (chromosomes) during cell
reproduction
3.
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composed of DNA and proteins, loosely
formed when cell is not dividing
Cytoplasm
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1.
cellular material outside the nucleus but
within the cell membrane
site of most cellular activities
composed of 3 major components
cytosol – semi-transparent fluid
composed mostly of water
2.
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inclusions
chemical substances present
but not functioning
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3.
types dependent on
function of cell
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fat droplets in fat cells
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melanin in the skin
primarily stored
substances
organelles
Organelles
mitochondria
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powerhouse of the cell
small, sausage-shaped
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move, change shape continuously
double membrane
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inner – smooth
outer – folds called cristae
Organelles
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Fluid enzymes and cristae
breakdown food.
Energy is released and used
to form ATP.
The more energy a cell
requires, the more
mitochondria it has.
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liver and muscles
Organelles
Ribosomes
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tiny round structures
site of protein synthesis
made up of proteins and one ribosomal
RNA
some attached, some free-floating
Organelles
Endoplasmic Reticulum (ER)
3.
minicirculatory system for cell
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series of tubules and sacs through cytoplasm
carry substances from one part of cell to
another
Organelles
2 Types:
1. Rough ER
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studded with ribosomes
transports proteins made by ribosomes
found in pancreas
Smooth ER
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no ribosomes, no protein synthesis
cholesterol synthesis
metabolize fat, detox drugs
found in liver, testes
Organelles
Golgi Apparatus
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UPS guys of cell
composed of closely packed membranebound sacs
packages, modifies, and transports
proteins from rough ER
found in salivary glands, pancreas
Organelles
Lysosomes
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intracellular digestive system
contain digestive enzymes
engulf bacteria other harmful substances
and get rid of them
removed used and worn out cell parts
found in white blood cells
Organelles
peroxisomes
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contain oxydase enzymes to digest fats
and detox alcohol, formaldehyde
convert dangerous free radicals into H2O2
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can mess up protein and nucleic acid structures
catalase then converts into H2O2 to water
Organelles
cytoskeleton
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provide framework or skeleton of cell
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shape, support, intracellular transport,
movement
made up of protein structures throughout
cytoplasm
microtubules, intermediate filaments,
microfilaments
Organelles
centrioles
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rod-shaped bodies close
to nucleus
direct formation of
mitotic spindle used in
cell division
centrosomes
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composed of two
centrioles
grow into spindle fibers
used during cell division
Organelles
vacuoles
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membranous sacs
holding area for substances entering the
cell
Other Cellular Structures
cilia – projections from surface of cell
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cylindrical shape
ex: move mucus in respiratory system
flagella – longer than cilia
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usually only one per cell
ex: sperm cells
microvilli – extensions on surface of cell membrane
 increase surface area for absorption
 ex: intestines, kidneys