Lecture 2 - macromolecules, cell theory, microscopy

Question 1

What are the molecules of life?

Answer 1

• Water
• Macromolecules

Question 2

Water:

Answer 2

• The H2O is the solvent of life
• it dissolve more molecules than any other solvent
• Its a polar molecule ( has opposite charges on either end)
• dissolves other polar and charged molecules

Question 3

What are the macromolecules?

Answer 3

• Carbohydrates ( polymers of sugars)
• Lipids (not polymers)
• Proteins (polymers of amino acids)
• Nucleic acids (polymers of nucleotides)

Question 4

Polymers

Answer 4

• Chains composed of molecules called monomers
• Monomers string together into polymers in a processes termed DEHYDRATION SYNTHESIS
• Polymers can be broken down via HYDROLYSIS
• ENZYMES primarily carry out these processes in living systems

Question 5

Most bio-polymers are not just straight chains of monomers

Answer 5

• The chains arrange into varied levels of higher-order structure
  Ex: DNA double helix, Protein folding, starch branching

Question 6

Amino acids

Answer 6

• R=sidechain
• Sidechain properties define the chemistry of proteins

Question 7

Polypeptides (primary structure)

Answer 7

Amino acids are linked by covalent bonds

Question 8

Secondary protein structure

Answer 8

• Hydrogen bonds between nearby amino acids cause the polypeptide to twist (alpha helix) or form sheets (beta sheets)

Question 9

Tertiary protein structure

Answer 9

Chemistry between sidechains causes higher-order folding.

Question 10

Quaternary protein structure

Answer 10

• Individual proteins interact to form complexes
• Again, determine by their structure and chemistry

Question 11

Polymers example: carbohydrates

Answer 11

The below are all polymers of glucose, but in different forms:
- Amylose (a component of starch)
- Cellulose
- Glycogen
- Chitin
These small differences lead to big differences in the resulting higher order structures
- slight difference in glucose bonds in these two polymers creates huge differences in their properties
- Adding things to the sides can also create huge differences in their properties

Question 12

What are the cell theory?

Answer 12

• All organisms are composed of one or more cells
• The cell is the basic structural and functional unit of all living organisms.
• Cells arise only from the division of pre-existing cells

Question 13

First observation of cells using microscopes - 1600’s

Answer 13

• Robert Hooke looked at cork cells
• Anton Van Leeuwenhoek made a better microscope and saw “many very little animacules, very prettily a-moving”

Question 14

Establishment of cell theory - 1800’s

Answer 14

• Theodore Schwann, Mattias Schleiden: (all living organisms are made of cells)
• Robert Remak, Rudolph Virchow: ( Proposed that all cells come from previous cells)
• Louis “LouLou” Pasteur: (Confirmed above hypothesis by demonstrating that the long-standing theory of spontaneous generation (aka Abiogenesis) was bunk.)