Cell Biology 1-3

Hypothesis 

A tentative explanation that can be tested and is falsifiable 

Cell theory 

  • All living organisms are composed of cells 

  • The cell is the basic unit of life 

  • Cells arise by the division of pre-existing cells

  • No spontaneous generation

Transmission electron microscope (TEM)

Microscope that passes an electron beam through very thin sections stained with metal atoms and primarily used to study the internal structure of cells. (sliced cross section)

Scanning electron microscope (SEM)

A microscope that uses an electron beam to scan the surface of a sample, coated with metal atoms to study topography. (3D image)

Polymers 

A long chain molecule consisting of repeating monomers connected by covalent bonds. 

Protein 

A long chain polymer that has been folded into a specific shape for a certain function. (biologically functional molecule consisting of one or more polypeptides folded into a 3D structure) 

Polypeptide 

A linear long chain molecule made up of amino acids with no specific function 

Protein vs polypeptide 

Protein = folded structure into specific shape so functional and contains polypeptides

Polypeptide = unfolded and no specific function

Polysaccharides 

A polymer of many monosaccharides, formed by dehydration reactions - Complex carbohydrates 

Eukaryotic cells size 

Eukaryotic cells (animals) 10-100µm ( 1µm = 10 ^-6 m) (

Bigger

Prokaryotic cells size 

Prokaryotic (bacterial cells) 1-100µm (0.001mm)

Smaller

Controlled experiment 

One that tests experimental and controlled groups in parallel 

Dehydration reaction 

The removal of water so that two monomers may join 

Micro (µ)

10^-6

How do scientific theories and scientific hypotheses differ from each other ?

Theories tend to be supported by a much greater body of evidence than a hypothesis 

Nano (n)

10^-9

What is the basic unit of a carbohydrate?

A monosaccharide 

What is tested directly during an experiment ?

A prediction