Lecture #1 Flashcards
The Definition of Life
- 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
A Cell is the Fundamental Unit of Life
- Cells are fundamental units of life
- Cells very in: shape/size, function, membrane, chemical requirements.
A Cell is the Fundamental Unit of Life part 2
- 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.
Prokaryotic
- 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
Eukaryotic
- 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
Nucleus
contains DNA
Endoplasmic reticulum (ER)
protein synthesis
Golgi apparatus
chemical modifications
Endosome
storage compartments
Lysosome/ Vacuole
breakdown cellular material “garbage”
Peroxisome
Reaction involving hydrogen peroxide
Mitochondria
- Energy factory of the cell (ATP)
- cellular respiration
Vesicles
transportation
Cytoskeleton
cell shaped and transportation
Chemical Components of Cells: A Review
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)
Elements Used in Biological Systems
Most common elements in biological systems (96.5%)
-H, C, O, N
Others
- Calcium (Ca), Sodium (Na), Phosphorous (P), and magnesium
Elements Used in Bio Systems Part 2
Covalent bonds - Electrons are shared - polar and non-polar Non-covalent bonds - Ionic: Electrons are transferred - Hydrogen: van der Waals/ Electrostatic
Covalent or Ionic Bond?
Number of electrons in the outer shell
- Ionic: accepting/giving one or two
- Covalent: more than one or two
Other Non-Covalent Bonds
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
Covalent vs. Non-Covalent bonds
Covalent bonds are shorter and much stronger than non-covalent bonds
Some molecules form acids and bases in water
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-].
Building Blocks of Biological Systems:
Sugars
-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)Fatty Acids
- 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
Nucleotides
-Building blocks of DNA and RNA
-Pyrimidines
Cytosine (C)
Thymine (T)
Uracil (U)
-Purines
Adenine (A)
Guanine (G)
Carriers of chemical energy
Amino Acids
Building blocks of proteins
20 amino acids
Polar
Non-polar
Charged
Joined together by peptide bond
N terminis- pos.
C terminis- neg
