1. Cells
1.Properties of water
Importance of being polar and non-polar
2.Prokaryotic and Eukaryotic Cells
3. How big are cells?
4. Eukaryotic cells
Differences between plant and animal cells
5. The parts of the cell
Plasma membrane
Organelles
• Function of each organelle
6. Cell diagrams
2. The Properties of Water (32-34)
The Properties of Water
Water is a polar molecule:
Oxygen side is slightly
negative
Hydrogen side is slightly
positive
When molecules have no
charges, they are
nonpolar
Figure 2.4
3. What Does Life Require?
The Properties of Water
Hydrogen bond: the weak attraction between
the hydrogen atom of one water molecule and
the oxygen atom of another
Water molecules tend to stick together:
cohesion
4. Water is a good solvent (p33,34)
The Properties of
Water
Water can dissolve
salts (ionically bonded
compounds) and
hydrophilic (water–
loving) molecules
because both the
water and these
molecules are polar.
Figure 2.6
5. Water is a polar solvent
The Properties of Water
Non-polar molecules, such as oil, do not
contain charged atoms.
These atoms are called hydrophobic (water–
hating).
Just as non-polar molecules do not mix with
polar solvents, polar molecules cannot dissolve
in non-polar solvents
• Water is not the only solvent!
6. Phospholipids
Type of lipid similar to a fat but with only 2 fatty
acid tails and phosphate “head”
The phosphate head is hydrophillic
The fatty acid tails are hyrophobic
7. Phospholipids
Due to the properties of
phospholipids, when exposed to
water they organize themselves
into a bi-layer.
Heads on the outside next to
the water
Tails inside away from the water
But the edges are also exposed to
water prompting the formation of
a sphere.
8. Plasma membrane
Where there is water,
the phospholipids line
up so that the head
(hydrophilic) is next to
the water and the tail
(hydrophobic) is away
from the water.
Because there is
water on both sides
you get 2 layers.
9. Plasma membrane (p44,45)
Plasma membrane
Also called a lipid bilayer
because it is comprised of 2 layers of lipids
Also
- Proteins
- Cholesterol
10. STUDY GUIDE
Know what kind of molecules will be dissolved in water and which will not and why.
Understand how the properties of phospholipids cause them to form the plasma
membrane
Q1. What kind of solvent is water?
Q2. What kind of molecules can water dissolve?
- 3 terms
Q3. What kind of molecules can watter not dissolve
- 3 terms
Q4. Describe the properties of the head group of a phospholipid
Q5. Describe the properties of the tails of a phospholipid
Q6. What happens when you put phospholipids in water?
- what is formed?
- why?
11. Measurements (nib)
1 meter = 3.28 feet
100 centimeters = 1 meter (cent means 1/100)
10 millimeter = 1 centimeters (milli means 1/1000)
1000 micrometers = 1 centimeter (micro means 1/1,000,000)
1000 nanometers = 1 micrometer (nano means 1/1,000,000,000)
Angstrom 10-10 meters
Picometer 10-12 meters
12. The scale of things
http://learn.genetics.utah.edu/content/begin/cells/scal
13. How many atoms?
How many atoms in a grain of salt?
a grain of salt contains about 1.2x1018 atoms,
half of which are sodium atoms. (The other half
is chlorine atoms, of course.)
1,200,000,000,000,000,000
1,000 one thousand (3 zeros)
1,000,000 one million (6 zeros)
1,000,000,000 one billion (9 zeros)
1,000,000,000,000 one trillion (12 zeros)
1,000,000,000,000,000 one quadrillion (15 zeros)
1,000,000,000,000,000,000 one quintillion (18 zeros)
14. Life on Earth
Prokaryotic and Eukaryotic Cells
All cells on Earth are either prokaryotic or
eukaryotic.
Prokaryotic cells are smaller and simpler in
structure.
– Typical prokaryote is around 5 μm
They probably resemble the earliest cells to arise
on Earth.
They often have a cell wall but it is not made of
cellulose like plants, it is made of a substance
called peptidoglycan.
15. How big are cells? (p44)
Bacteria are prokaryotes, they are smaller
than animal or plant cells which are
eukaryotic
Prokaryotic means NO nucleus
Eukaryotic cells have a nucleus, in
which they keep DNA
16. Life on Earth
Prokaryotic and Eukaryotic Cells
Prokaryotes do not have a true nucleus.
They don't have organelles
Figure 2.17b
17. Life on Earth
Prokaryotic and Eukaryotic Cells
Eukaryotic cells are much more complex.
−
Have true nucleus surrounded by a membrane
−
Also have (in most cases) membrane-bound organelles
with specialized jobs
18. STUDY GUIDE
Know the difference and similarities between prokaryotes and eukaryotes
Q1. Which one does not have a nucleus?
Q2. Which one has organelles?
Q3. Which one is bigger?
Q4. How big is a typical prokaryote and eukaryote?
Q5. In what scale do we describe the size of cells?
Q6. Know which is bigger and smaller
–
10cm
Arrange these from smallest to biggest:
50mm
1m
600nm
90μm
20. Differences
Can you find the differences between plant and
animal cells?
Except:
Cytoplasm – the entire contents of the cell
(except the nucleus) surrounded by the plasma
membrane
Cytosol – the fluid portion of the cytoplasm
21. Look inside a cell
Tour of an animal cell
Tour of a plant cell
22. - surrounds the cell
- regulate what comes in and what goes out
- semipermeable (more specifically it is partially
permeable)
- maintain an internal environment different from the outside
– Hydrophobic core
• many polar molecules cannot cross
24. - all plant cells have a cellulose cell wall
- not found in any other cells
- tough often flexible
- in conjunction with pressure exerted by the vacuole gives
the cell rigidity
- like air in a tire
25. - only found in eukaryotes, 2 membranes
- houses the DNA
- studded with holes called nuclear pores
- Through which the DNA can “communicate” with the cell
- nucleolus is where ribosomes are built
26. - bounded by a double membrane
- important in the conversion of food into usable cellular energy –
cellular respiration
- usable cellular energy is the molecule ATP
- folded up inner membrane increases surface area
27. STUDY GUIDE
Be able to identify in a cell diagram and know the function of the
following:
a. Plasma membrane
b. Cell wall (plants)
c. Nucleus
d. Mitochondria
28. - only found in plants and green algae (plant ancestors)
- site of photosynthesis
6CO2+6H20 → C6H12O6 + 6O2
- 2 membranes
- pigments (chlorophyll) in chloroplast make plants green
29. - membrane enclosed sac of digestive enzymes
- recycles molecules and damaged organelles
30. - found in both prokaryotic and eukaryotic cells
- take instructions from DNA and build proteins
- can be free floating or attached to the endoplasmic reticulum
31. - 2 types – rough and smooth
- Rough ER – covered in ribosomes
- major site for protein production in the cell
- proteins made here are usually secreted by the cell or
become part of the plasma membrane
- Smooth ER – no ribosomes, varied function
- detoxifying harmful substances, lipid synthesis
- vesicles are pinched off pieces of ER
32. - protein containing vesicles from the ER fuse with golgi
- the proteins are modified, sorted, packaged and sent out to their
destinations in new vesicles
34. - protein containing vesicles from the ER fuse with golgi
- the proteins are modified, sorted, packaged and sent out to their
destinations in new vesicles
35. STUDY GUIDE
Be able to identify in a cell diagram and know the function of the
following:
e. Chloroplast (plants)
f. Lysosome
g. Ribosomes
h. Rough and smooth ER
i. Golgi apparatus
36. - found in most eukaryotic cells, though it is absent in higher plants
and most fungi
- microtubule formation
- cell division – move chromosomes around
- cilia and flagella
37. - protein fibers
- give shape to the cell
- hold and move organelles
- including transport vesicles
- involved in cell movement
38. - can occupy 90% of a plant cell
- contains many dissolved molecules
- eg sugars and pigments
- pressure of vacuole pressing against the plant cell wall gives
structural support
- allows plants to stand upright
40. STUDY GUIDE
Be able to identify in a cell diagram and know the function of the
following:
j. Centrioloes
k. Cytoskeleton
l. Central vacuole (plants)
Be able to relate the organelle with the factory job function
