Download cellular basis of life

Theme 3.
Physical, chemical and cellular
basis of life.
2.01 Organic Molecules
• Contain carbon
• Molecules of living things (or once living)
• Make up all living things
• Large & complex
• Examples: mouse, wood, apple, bread,
paper, bacteria
Carbohydrates
• C-H-O
• Long chains of simple sugars
(monosaccharides)
• Monosaccharides (simple
sugar): glucose, fructose,
galactose, ribose
• form polysaccharides
• Polysaccarides (complex):
cellulose, glycogen, starch
• IMPORTANT FUNCTION:
provide energy for living
things
•
•
•
•
•
•
C-H-O-N
long chains of amino acids
Joined by peptide bonds
Forms a polypeptide
(Examples are enzymes,
insulin and hemoglobin)
IMPORTANT FUNCTION:
provide the structural &
functional components
of cells; growth; repair
of cells/tissues
Proteins
Lipids
• C-H-O
• Subunits are fatty
•
•
•
•
acids and glycerol
EX: Fats, Oils, Waxes
Phospholipids,
Triglycerides,
Cholesterol
Parts of Cell
membranes, sex
hormones
IMPORTANT
FUNCTION: longterm energy
storage; insulation
• C-H-O-N-P
• DNA & RNA
• Subunits are nucleotides
• Composed of sugars,
phosphates, and
nitrogenous bases
• DNA (A,C,T,G)
• RNA (A,U,C,G)
• IMPORTANT
FUNCTION: Carries
genetic information;
instructions on how to
make proteins
Nucleic Acids
Food Tests
Iodine is a test for
starch. It starts as
a rust color and
turns black or
blue/black.
Benedict’s solution is a
test for simple sugars:
monosaccharides.
It starts blue and
turns red if heated.
Food Tests
Lipids turn brown
paper translucent.
Biuret is a blue
solution that turns
purple in the
presence of
proteins
2.02 Structure and Function of
Cells
Cells are the basic unit
of all living things.
All living things are
made of cells.
Cells come only from
other living cells.
Cytology is a branch of biology which deals with
the study of structural and functional
organization of the cell as the unit of living
matter. The subject of cytology is the cell of
unicellular (bacteria, protists, algae, fungi), as
well as multicellular organisms (animals, plants,
fungi) organisms. Cytology studies the structure
and function of cells, their chemical
composition, the relationship with each other in
a multicellular organism, reproduction and
development, adaptations to the environment.
Cell Organelles
Nucleus – contains
DNA, regulates the
functions of the cell.
Plasma membrane regulates what goes
into and out of the
cell.
Ribosomes- where
proteins are made
Cell Organelles
Mitochondria – where
cellular respiration
occurs; energy is
released here
Cell Organelles
Cell wall – made of
cellulose, protects
plant cell and gives it
shape.
Vacuoles – store food,
water or waste.
Large in plant cells,
small in animal cells.
Chloroplast – where
photosynthesis
occurs.
Plant Cells vs. Animal Cells
Cell wall
Large vacuole
Chloroplasts
Rectangular shape
No cell wall
Small vacuoles
No chloroplasts
Varied shape
How do you focus?
How do you let more light
in?
How do you locate your
specimen?
MAGNIFICATION:
Eyepiece x Objective =
Total Magnification
Examples:
10x x 4x = 40x
10x x 10x = 100x
Microscopes
Hierarchy of cell organization
Cells 
Tissues 
Organs 
Organ systems
Structure and Function
Nerve cells
structure is well
suited to
carrying nerve
impulses through
the body.
Structure and Function
Red blood cells
smooth disk
shape is well
suited to
traveling through
blood vessels.
(carry oxygen)
Structure and Function
Muscle cells are long & spindle shape; allows for
expanding & contracting to create movement
need a great deal of energy, so they have
many mitochondria located in them.
Cell Communication
Messages can travel from
one nerve cell to
another.
A neuron releases
neurotransmitters to
send a message to a
muscle cell to
stimulate the muscle
to contract
Cell Communication
G proteins act like relay batons to pass messages from circulating hormones
into cells. A hormone (red) encounters a receptor (blue) in the membrane of
a cell.
A G protein (green) becomes activated and makes contact with the receptor
to which the hormone is attached.
The G protein passes the hormone's message to the cell by switching on a
cell enzyme (purple) that triggers a response.
2.03 Cell Transport and
Homeostasis
Homeostasis:
maintaining a
stable internal
environment
Plasma
Membrane:
Maintains
homeostasis
Semi-permeable membrane
Allows small molecules
to pass through but
not large ones.
Semi permeable membrane
Example – regulation of
temperature
Sweating- release
Perspiration to cool
Body down
Example – regulation of
temperature
Shivering: movement of
muscles generate
heat
Examples – pH of blood
Buffers in blood help to
keep blood from
becoming too acidic
or too basic.
Example – blood glucose level
Insulin removes glucose
from your blood by
turning it into
glycogen in your liver
and muscles.
Glucagon puts glucose
into your blood by
converting glycogen
into glucose.
Example – water balance
Too much water?
Urinate frequently and it
is very dilute.
Too little water?
Urinate infrequently and
it is very
concentrated.
KIDNEYS: regulate
water balance in body
PASSIVE
TRANSPORT
(no energy required to
move molecules)
a. Diffusion
b. Osmosis
c. Facilitated diffusion
ACTIVE TRANSPORT
(energy – ATP - is
required to move
molecules)
Transport (types)
Diffusion
- The movement of
molecules from an
area of high
concentration to an
area of low
concentration.
- CONCENTRATION
GRADIENT: difference
in conc on 2 sides of
a barrier <H/L>
Osmosis
Diffusion of
water thru
a membrane.
Movement
continues until
Equilibrium is
reached
Facilitated Diffusion
• Movement of
•
molecules too large to
pass through
membrane without
help…protein carrier
molecules in cell
membrane help move
in these molecules
EX: glucose
Active Transport
Movement of molecules
from an area of low
concentration to high
concentration.
Movement against the
concentration
gradient
Requires Energy!
Examples of transport
RBC in
Salt water
RBC in
normal blood
RBC in
distilled water
Examples of transport
2.04 Characteristics of
Enzymes
• Enzymes are
protein molecule
that function as
biological catalysts
• They speed up
cellular reactions
• End in -ase
HOW ENZYMES WORK…
• Specific fit with substrate
•
•
•
so each enzyme has
special job.(lock and key)
Meet at enzymes active
site.
Enzymes aren’t used up
so they can be re-used
after it has done its job.
Necessary for all
biochemical reactions.
Effects of the environment on enzymes
• Environmental
•
•
changes can destroy
enzymes (change
their chemical
structure and make
them ineffective)
Enzyme is denatured
pH, temperature
2.05 Respiration and
Photosynthesis
ATP
• Adenosine Tri-phosphate
• Energy molecule for cell
•
•
activities
Made from ribose,
adenine, and three
phosphate molecules
Energy is stored when
phosphate bond is
formed, and released
when the bond is broken
(makes ADP)
• Important cycle in
respiration and
photosynthesis
ATP
When high energy
phosphate bond is
broken  energy
released and ADP
made.
Cellular Respiration
All living
organisms respire
to release energy
Aerobic Respiration
OXYGEN
REQUIRED
Occurs in
MITOCHONDRION
36 ATP’s produced
C6H12O6 + O2  CO2 + H2O + ATP
Glucose & oxygen needed
Carbon dioxide, water, energy produced
Anaerobic Respiration
• Without Oxygen
• Not as efficient; only
•
2 ATP’s
2 Types (also called
FERMENTATION)
– 1) alcoholic
fermentation produces
alcohol (yeast)
– 2) lactic acid
fermentation produces
lactic acid (muscle
cells and bacteria)
Compare and Contrast
Anaerobic Respiration
Without oxygen
Cytoplasm
2 ATP
Yeast, bacteria
24/7
Aerobic Respiration
With oxygen
Mitochondria
36 ATP
Multicellular organisms
24/7
Photosynthesis
• Plants convert solar
•
•
•
•
energy from sun into
chemical energy (ATP)
Occurs in chloroplast
Plants, algae, blue-green
bacteria
Only occurs during the
day
What might effect the
rate of photosynthesis?
Amount of CO2 in atmosphere