Week 1 Biology

What is life

Composed of cells

Regulate its internal environment take in and use energy and respond to its environment

Name species

Genus | particular species within genus

Taxonomy: branch that names and classifies species, hierarchy --> to identify the evolutionary history and relationships of organisms

Domains:

Bacteria

Archaea: Live in extreme environments

Eukarya: More complex cells

Protist: single cells organism

Plants: produce own food by photosynthesis

Fungi: decompose organic wastes and absorb the nutrients into their cells

Animals: Obtain food by eating other organisms

 

Hierarchy of organization

Emergent properties: Properties that were not present at the preceding level

  1. Biosphere: Earth

  2. Ecosystem: all organisms in a particular area and physical components

  3. Community: All organisms in an ecosystem

  4. Population: all the individuals of a particular species living in community

  5. Organism

  6. Organs and organ systems: Body parts that perform a specific function

  7. Tissue: group of similar cells performing a function

  8. Cell: fundamental structural unit of life

  9. Organelle: membrane-enclosed functional structure in cell

  10. Molecule: Chemical structure consisting of two or more units called atoms

 

Data: recorded observations

Quantitative data: numerical measurements

Theory: broader scope and is supported by a large and usually growing body of evidence

 

Independent variable: factor that is manipulated

Dependent variable: factor that deepens on or is affected by the first.

Controlled experiment: experimental group is compared with a control group.

 

Clinical trials must be cut short if preliminary results show that the treatment is either significantly harmful or significantly beneficial to the participants, because it would be unethical to knowingly harm participants or withhold effective treatment.

 


 

 

 

Scientists usually speak of "discoveries," whereas engineers more often speak of "inventions." These two fields, however, are interdependent. Scientists use new technology in their research , and scientific discoveries often lead to the development of new technologies

 

OBSERVATION #1: Individual variation. Individuals in a population vary in their traits, many of which seem to be heritable (passed on from parents to offspring).

OBSERVATION #2: Overproduction of offspring. All species can produce far more offspring than the environment can support. Competition for resources is thus inevitable, and many of these offspring fail to survive and reproduce.

INFERENCE # 1: Unequal reproductive success. Individuals with inherited traits best suited to the local environment are more likely to survive and reproduce than are less well suited individuals. INFERENCE #2: Accumulation of favourable traits over time. As a result of this unequal reproductive success over many generations, a higher and higher proportion of individuals in the population will have the advantageous traits.

 

Similarly, in biological systems, structure (the shape of something) and function (what it does) are almost always related, with each providing insight into the other.


Matter is defined as anything that occupies space and has mass.

 

A compound is a substance consisting of two or more different elements combined in a fixed ratio.
 


Iodine is an essential component of a hormone produced by the thyroid gland. An iodine deficiency in the diet causes the thyroid gland to grow to abnormal size, a condition called goiter.

 

Use the boron model to explain.

Electron shells.

Valence electrons determine the chemical properties of atom.

 

Chemical bonds:

Ionic bond

Covalent bonds

Bonding capacity/ valence

 

Electronegative is measure of attraction

Nonpolar covalent bonds.

Polar covalent bond

 

Hydrogen bond: weak bond

 

Radioactive Isotopes

Biologists often use radioactive tracers to follow molecules as they undergo chemical changes in an organism.

Tracer

Damage: particalse trown off can damage DNA

 

Cohesion: tenedency of molecules of same kind to stick together

Surface tension: difficulty to strecht or break surface of a liquid.

Adhesion: clinging of one substance to another.

 

Hydrogen bonds forms --> releasing heat

Hydrogen bonds brake --> heat is absorbed

 

Evaporative cooling: substance evaporates, surface remains behind cools down.

 

Ice: three dimensional cristal that makes it the water molecules are further appart than liquid.

 

Solution: Solvent (water), solute( substance)

 

pH of humans 7.4. Sustained by buffers.

 

Ocean acidification: CO2 dissolving in seawater. Lower pH. Impacts coral reef

 

Chapter 3

 

Organic compounds: Carbon-based molecules

Isomers

Hydrocarbons: carbon and hydrogen


 

Macromolecules

Polymers of monomers --> dehydration reaction

Breaking --> hydrolysis

Enzymes: speed up chemical process

 

Carbohydrates

Hydrophilic

Monosaccharides

Glucose, fructose 6

Pentose 5

Hexoses 6

(Some multiplication of CH2O)

Disaccharide

Maltose

Polysaccharides

Starch: storage in plants.

Glycogen: Animals. Highly branched.

Cellulose: walls of enclose plant cells. Cable like microfibrils.

Chitin: structural used by insects and crustaceans to build exoskeleton.

 

Lipids

Hydrophobic

Fat/triglyceride: Large lipids

Glycerol

Fatty acids

Unsaturated: double bond


Hydrogenation: unsaturated--> saturated. --> trans fats (health risks)

Energy storage

Phospholipids: cell membranes

Hydrophobic tails, hydrophilic heads.

Steroids:

Cholesterol: cell mambranes


Anaboic steroids

Synthetic varients of male hormone testosterone

 

Proteins

Amino acids

Enzyme, transport, defensive, signal, chemical messenger

Globular: Compact spherical shapes

Fibrous proteins: Long and thin

Lysozyme

Denaturation: protein unravels losing function.


20 Amino acids

Peptide bond

Hydrophobic amino acids cluster together in center, hydrophilic face outside.

Disulfide bridges (covalent bonds)

 

Primary structure: sequence of amino acids

Secondary structure: segments of chain then coil or fold (betasheets alfa helix)

Tertiary structure: overall three-dimensional shape

Quaternary structure: more than one polypeptide chain

 

DNA


Nuclei acids

Nucleotides

Adenine, Thymine, Cytosine, Guanine (A-T and C-G)

Thymine (T) and cytosine (C) are single-ring structures called pyrimidines.

 Adenine (A) and guanine (G) are larger, double-ring structures called purines.

Double helix

sugar-phosphate backbone

RNA

Uracil (not T)

Single strand

Gene expression: directing the synthesis of proteins.

 

Transcription: synthesis off RNA under the direction of DNA

Tra

nslation: syntehsis of protein under the direction of RNA\

 

a gene: a region of DNA that can be expressed to produce a functional product that is either a polypeptide or an RNA molecule. T

 

Prions: infectious proteins

Retrovirus: reverse transcriptase, RNA as a template for making DNA, which then insert into a host chromosome.