Lecture #1

Question 1

The Definition of Life

Answer 1

• highly organized
  - When compared to natural inanimate
  objects
• maintains homeostasis
  - constant internal environment
  -reproduce
  -grow/develop from simple beginnings
  -take energy/matter from the environment and transform it
  -respond to stimuli
• adapt to their environment

Question 2

A Cell is the Fundamental Unit of Life

Answer 2

• Cells are fundamental units of life

- Cells very in: shape/size, function, membrane, chemical requirements.

Question 3

A Cell is the Fundamental Unit of Life part 2

Answer 3

• Microscopes allow us to view cells and their components.
• Light microscope
  - Visual light is used to illuminate the
  specimen.
• Fluorescence microscope
  - Uses specific wavelengths of light to illuminate fluorescent dyes.
• Electron microscope
  - beams of electrons are used to visualize the specimen. ( High resolution) See inside the cell, and cellular structures.

Question 4

Prokaryotic

Answer 4

• single celled
• no membrane bound organelles
• Genome: circular piece of double- stranded DNA
• Extra circular pieces of DNA called plasmids
• Ex: Archaea and Bacteria/Eubacteria

Question 5

Eukaryotic

Answer 5

• Unicellular
• Bigger than prokaryotes
• several membrane bound organelles
• genome is contained in the nucleus
• Ex: amoebae, yeast, humans
• Everything happens in cytoplasm
• DNA in mitochondria; not all DNA in nucleus

Question 6

Nucleus

Answer 6

contains DNA

Question 7

Endoplasmic reticulum (ER)

Answer 7

protein synthesis

Question 8

Golgi apparatus

Answer 8

chemical modifications

Question 9

Endosome

Answer 9

storage compartments

Question 10

Lysosome/ Vacuole

Answer 10

breakdown cellular material “garbage”

Question 11

Peroxisome

Answer 11

Reaction involving hydrogen peroxide

Question 12

Mitochondria

Answer 12

• Energy factory of the cell (ATP)

- cellular respiration

Question 13

Vesicles

Answer 13

transportation

Question 14

Cytoskeleton

Answer 14

cell shaped and transportation

Question 15

Chemical Components of Cells: A Review

Answer 15

The chem of life:

• based on o chem
• reactions occur within an aqueous environment.
• extremely complex
• coordinated by the actions of polymeric molecules.
• tightly regulated (spatially and temporally)

Question 16

Elements Used in Biological Systems

Answer 16

Most common elements in biological systems (96.5%)
-H, C, O, N
Others
- Calcium (Ca), Sodium (Na), Phosphorous (P), and magnesium

Question 17

Elements Used in Bio Systems Part 2

Answer 17

Covalent bonds
  - Electrons are shared 
   - polar and non-polar 
Non-covalent bonds
   - Ionic: Electrons are transferred 
   - Hydrogen: van der Waals/ Electrostatic

Question 18

Covalent or Ionic Bond?

Answer 18

Number of electrons in the outer shell

• Ionic: accepting/giving one or two
  - Covalent: more than one or two

Question 19

Other Non-Covalent Bonds

Answer 19

Van der Waals/Electrostatic 
   - dipole moment 
   - Based on weak charges 
   - Atomic scale vs molecular scale 
Hydrogen bonding 
   - polar vs. non-polar bonds 
   - N, O, F

Question 20

Covalent vs. Non-Covalent bonds

Answer 20

Covalent bonds are shorter and much stronger than non-covalent bonds

Question 21

Some molecules form acids and bases in water

Answer 21

pH scale measures the [H+}
Acid: Releases a proton (s) when dissolved in water. Increase the [H+] and therefore the [H30+].
Base: Accept a proton (s) when dissolved in water. Decreases the [H+] and therefore increases the [OH-].

Question 22

Building Blocks of Biological Systems:

Sugars

Answer 22

-Energy source
    glucose, glycogen and starch 
- structural source
   cellulose and chitin 
- Mono vs. di- saccharides 
     Glucose vs sucrose (glucose+fructose) 
     Glycosidic bond 
      Oligosaccharide vs polysaccharide 
      3-50 monomers vs 100s/1000s monomers 
-Used to modify other molecules 
   Glycoproteins 
    Glycolipids (fats that have sugar)

Question 23

Fatty Acids

Answer 23

• Concentrated food storage
  -Lipid
  fat soluble
• amphipathic
• Stored as triacylglycerol droplets
  3 fatty acid chains + glycerol molecule
  Hydrophobic
• Unsaturated vs saturated
• Phospholipid
  Formation of membranes
  Highly amphipathic

Question 24

Nucleotides

Answer 24

-Building blocks of DNA and RNA
-Pyrimidines
Cytosine (C)
Thymine (T)
Uracil (U)
-Purines
Adenine (A)
Guanine (G)
Carriers of chemical energy

Question 25

Amino Acids

Answer 25

Building blocks of proteins  
20 amino acids 
    Polar 
    Non-polar 
    Charged 
Joined together by peptide bond  
N terminis- pos. 
C terminis- neg