1. 2.1 Molecules to Metabolism
Do your Socrative quiz!

2. Highest level of certainty in science corroborated unquestionably
The process of science is based on a system of:
Making hypotheses
Testing them through rigorous collection of empirical evidence (can be measured and recorded)
Peer-review of data
Statistical analysis
Replication
Acceptance
THEORY!
Highest level of certainty in science
acceptance
corroborated unquestionably
repeated
corroborated ?
hypothesis
testing
observations
hypothesis
hypothesis ?
not corroborated
(evidence does not support hypothesis)
“It’s only a theory”

3. The scientific process

4. Falsifiability The purpose of science is to explain and predict.
A key aspect of this is falsifiability.
Falsifiability is the possibility that an assertion could be shown false by a particular observation or physical experiment.
This does not mean it is false; rather, it means that if the statement were false, then its falsehood could be demonstrated.

5. All humans live forever.
No human lives forever.
All humans live forever.
Is this falsifiable?
No.
Is this falsifiable?
Falsifiable
It does not seem possible to prove wrong.
In theory, one would have to observe a human living forever to falsify that claim.
The presentation of just one dead human could prove the statement wrong.
This excludes metaphysical assertions about souls, which are not falsifiable.
Some statements are only falsifiable in theory, while others are even falsifiable in practice.
For example, "it will be raining here in one billion years" is theoretically falsifiable, but not practically so.

6. Karl Popper and his philosophical analysis of the scientific method
A hypothesis, proposition, or theory is "scientific" only if it is, among other things, falsifiable.
Unfalsifiable statements are non-scientific.
Falsifiability is a special case of the more general notion of criticizability.

7. Urea was discovered in the 1720’s in urine.
For example:
Urea was discovered in the 1720’s in urine.
In 1828 Friedrich Wohler synthesized urea!
Silver isocyanate
It was assumed to be a product of the kidneys.
Ammonium chloride
At the time, it was thought that these compounds could only be made with the help of a “vital principle”.
This “vital principle” causes the phenomena of life to happen, rather than chemical or physical forces.
If urea had been synthesized without a “vital principle” then other organic compounds could as well.

8. You must be able to draw and identify molecular diagrams of some basic organic compounds.
These can be represented in lots of different ways. Look at the following diagrams, they all represent the same thing. How?

9. You must be able to draw and identify molecular diagrams of some basic organic compounds.
These can be represented in lots of different ways. Look at the following diagrams, they all represent the same thing. How?

10. Carbohydrates Monosaccharides Disaccharides
Can be in a chain or a ring 2× as many H’s as C’s
Sucrose = glucose + fructose
Glucose
Lactose = glucose + galactose
Lactose
Maltose = glucose + glucose
Galatose

11. Model how monosaccharides combine to form disaccharides through condensation reactions
OH + H =

12. Phospholipids
Lipids
Triglycerides

13. Model how fatty acids and glycerol combine to form triglycerides through condensation reactions
OH + H =

14. Amino Acids
Serine
Glutamine
Tyrosine

15. Model how amino acids combine to form polypeptides through dehydration reactions
I think you get the idea!
Pick three amino acids bond them through condensation reactions.

16. Which molecule represents ribose? What is molecule B?
Question from Paper 1
Which molecule represents ribose?
What is molecule B?
What is molecule C?

17. Which structure represents an amino acid?
Question from Paper 1
Which structure represents an amino acid?

18. ii. Generalized fatty acid ii. Generalized amino acid
Question from Paper 1
Which molecule is:
i. ribose
ii. Generalized fatty acid
ii. Generalized amino acid
Discuss which two molecules are most similar in structure.

19. What is the name of this molecule? What are each of the parts called?
Biology Journal 8/28/2013
What is the name of this molecule? What are each of the parts called?

20. Drawing structures Glucose – C6H12O6 6-membered ring with a side chain
5 carbons in the ring, one carbon in the side chain
#C’s with 1 on the right, then clockwise
Hydroxyl’s (-OH) on C’s 1, 2, 3, 4 point down, down, up, down
Ribose – C5H10O5
5-membered ring with side chain
4 carbons in the ring, one carbon in the side chain
#C’s with 1 on the right, then clockwise
Hydroxyl’s (-OH) on C’s 1, 2, 3, point up, down, down
Generalized amino acid
C atom in the center is bonded to four things
Amine group –NH2
Carboxyl group – COOH
Hydrogen atom –H
R group
Saturated fatty acid
C’s form an unbranched chain
All single bonds in a saturated fatty acid
# of C’s is between 14 and 20
At one end of the chain, the C is part of a carboxyl group
At the other end of the chain, the C is bonded to three H atoms
All other C’s are bonded to two H atoms