9/13/2016
Bio100 (Dr Paddack) Lecture 6 (9/12/16)
I. Building blocks of life (Ch 3)
A. Water – why is it important to life
B. Carbon – why is it the basis of life?
C. Organic Compounds
1. Sugars/Carbohydrates
2. Lipids
a. Fats
b. Phospholipids
c. Steroids
3. Proteins
4. Nucleic Acids
a. DNA
b. RNA
c. ATP
II. Membrane structure & function (Ch 5)
A. Membrane structure
B. Getting stuff in/out of cells
1. Passive transport
a. Diffusion
b. Osmosis
c. Facilitated diffusion
2. Active transport
3. Exocytosis
4. Endocytosis
Why is life carbon-based?
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Carbohydrates: carbon, oxygen, hydrogen
Biomolecules
Molecules that are essential to cell structure and function, and
that are constructed by living organisms
Four types of large biomolecules
sugars
lipids
proteins
nucleic acids
Functions:
1) Glucose storages for later use as fuel (polysaccharides, eg
starch)
2) Physical structure (eg, cell walls; chitin)
Figure 3.7
Lipids
carbon, oxygen, hydrogen, & sometimes
others (phosphorus, sulfur, etc)
Fats
Glycerol
Three types of lipids:
1) Fats
2) Phospholipids
3) Steroids
‘Role’ of fats
- Long term energy storage
Fatty acids
2x as much energy as
sugar (per unit weight)!!
Functions of Fats
protection
waterproofing
buoyancy
insulation
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Fat
Vs.
(triglyceride)
Phospholipids
Phosphate
group
Glycerol
Phosphate
group
Glycerol
lipid bilayer –
cell membranes
Hydrophilic heads
Hydrophilic
head
Water
Hydrophobic tails
Symbol for phospholipid
Hydrophobic
tail
Lipids
Water
Proteins
carbon, oxygen, hydrogen, nitrogen
Three types of lipids:
1)Fats
2)Phospholipids
3)Steroids
Steroids: lipids that act as signaling molecules
inside and among cells. Their presence initiates
expression of certain genes (DNA segments).
enzymes
Protein Functions
hemoglobin
Poisons, etc
hormones
structure
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Nucleic Acids:
carbon, oxygen, hydrogen, phosphorus,
nitrogen
a nucleic acid – energy currency of organisms
DNA
ATP – cell ‘currency’
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Lecture 6 (9/12/16): Study Questions
1. Why is water so important for life?
2. Describe why carbon is capable of bonding with
other molecules (thus creating an excellent ‘skeleton’
for biomolecules).
3. Define isomer.
4. Define organic compound –list the 2 elements in all
organic compounds and the 3rd element in most
organic compounds.
5. List the elements in each of these types of organic
compounds: carbohydrates, lipids, proteins, nucleic
acids.
6. List 4 functions of fats
7. How do fats differ from phospholipids?
8. Understand how the lipid bilayer forms.
9. Define steroid – what type of compound is it?
Provide 1 example.
10. List 5 different functions of proteins.
11. Define enzyme – why are they important?
12. Why do proteins need a specific range of
temperature & pH to function? (think of your lab from
this week)
13. Define: DNA, gene, RNA, ATP
14. Define: diffusion, osmosis (last week’s lab).
15. Be able to determine which direction osmosis will
occur when a cell is in water that is saltier and when in
water less salty than it (from last week’s lab) –
remember, salt follows water.
16. Most molecules are too large (and too charged) to
pass thru the lipid bilayer. List 2 different ways that
molecules can be brought into or out of a cell.
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