Download The Cell: the Basic Unit of Life

The Cell: the Basic
Unit of Life
Biotech Unit 2
All living things are composed of
cells
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Made up of the same
chemicals
Use same basic design and
building materials
Carry out same processes in
similar ways
Use DNA to store and
transmit information and for
reproducing
Use many different types of
proteins to carry out their
many processes
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Introduction to Cells YouTube
Cells grow
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Increase in size and this requires building material and energy
Break down large complex food molecules
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Proteins  amino acids
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Peptide bonds
Lipids - fatty acids and glycerol ex. Steroid, phosolipid layer
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ex. Enzymes, hemoglobin, insulin
glycerol
Carbohydrate  monosaccharide
polysaccharides
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Nucleic Acid nucleotides
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ex. Glucose, starch,
cellulose, glycogen
ex. DNA and RNA
Deoxyribose, phosphate nitrogen base
This process of breaking down large molecules for building
blocks and then using these materials and energy into molecular
manufacturing is known as metabolism
Cells Reproduce Themselves
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Mitosis- all eukaryotic
cells except gametes
(sex cells)
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Meiosis- eukaryotic
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cells that are gametes
Binary fissionprokaryotic cells
Cells Maintain Their Internal
Environment- Homeostasis
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Cell’s internal
environment is very
different from their
external environment.
They control amounts of
salts, chemicals and
molecules
Cells must expend
energy to maintain these
differences
Cells Respond to their External
Environments
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When salt concentration
change, they respond
In a harsh environment,
a bacteria will move
toward food and away
from toxins
A plant cell will react to
an insect eating it by
releasing a toxic chemical
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Cells must sense the
change respond
Cells Communicate
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EX- nerve cells give muscle
cells the signal to contract
A cell in tissue senses when it
is touching another cell and
stops growing- except in
cancer cells
Certain disease causing
bacteria signal to each other
to determine when their
population is large enough to
attach
A hormone produced in one
organ affects certain cells
In Multi-celled Organism, Cell
Specialize
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Cell differentiation- during development, a
single fertilized egg divides and becomes
specialized
Cells Require a Constant Supply of
Energy
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Cells breaking down, building and rebuilding
molecules and maintaining a stable internal
environment all require energy.
Cells supply energy from breaking down
macromolecules.
Photosynthesis, chemosynthesis, and cellular
respiration
Cell Processes
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Involve chemical reactions- controlled by
enzymes
Occur in a series of small steps beginning with a
starting material and ending up with an end
product. This is called a pathway