Lecture 1:
How big are cells and what are they made of?
What are cells?
- Cells are the fundamental unit of all living things in the Earth
- They take nutrients and free energy from their surroundings and make copies of
themselves
What is cell theory?
1. All living things are composed of cells and cell products - Theodor Schwann & Matthias
Jakob Schleiden
2. Cells are the basic units of structure and function in living things
3. All cells are created through division of pre-existing cells - Barthelemy du Mortier
History of development of cell theory
Antonie van Leeuwenhoek 1632 - 1723 - began to build his own microscopes, built best
microscopes available anywhere at the time. First person to see bacteria, blood cells,
protists, algae etc.. ‘little animals’
Robert Hooke 1665 - Published a book micrographia - described slices of cork on
microscopes, reminded him of prison cells - used to name living cells.
Germ theory of disease - Koch’s postulates
Microorganism must be found in abundance in all organisms suffering from the disease, but
should not be found in healthy organisms.
Microorganism must be isolated from diseased organisms and grown in pure culture.
Cultured microorganisms should cause disease when introduced to a healthy organism.
Microorganisms must be reisolated from the inoculated, diseased experimental host and
identified as being identical to the original specific causative agent.
-
What are the Universal features of all cells?
- Evolution from a common ancestor
- All cells are surrounded by a plasma membrane
- Cells exchange molecules with their surroundings e.g: sugars, amino acids, ions, water
usually via transport proteins
- Cells communicate
- All cells store their genetic information as DNA
- Protein synthesis - cells translate RNA into protein in the same way
- Organelles of eukaryotic cells
- Life is a ‘pattern in a flux’ molecules are constantly being exchanged
- The DNA fragment corresponding to 1 protein is 1 gene
- Cells are made from a few simple building blocks
, What is Taxonomy ?
- The academic discipline of defining groups of biological organisms on a basis of shared
characteristics
- the branch of science concerned with classification, especially of organisms; systematics
What is Phylogenetics?
- study of evolutionary relationships among groups of organisms
What is Homeostasis?
- The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting
its physiological processes
- Almost all molecules in the human body are continuously replaced, exception: DNA
Lecture 2:
Biological Molecules:
What are biological molecules?
- Life is based on reactions between molecules
- Biological molecules are carbon based (except for some small inorganic molecules)
- Can be classified into a no of categories
A summary of biological molecules:
Small Large (macromolecules)
sugars polysaccharides
amino acids proteins
nucleotides nucleic acids (DNA, RNA)
lipids/fats associate to form membrane
Small molecules often play at least 2 roles, what are they?
- as building blocks for molecules
- as some other specific function in their own right
Composition of cell:
Proportion of total cell weight
Water 70
Inorganic ions 1
Small organic molecules 3
Macromolecules 26
How big are cells and what are they made of?
What are cells?
- Cells are the fundamental unit of all living things in the Earth
- They take nutrients and free energy from their surroundings and make copies of
themselves
What is cell theory?
1. All living things are composed of cells and cell products - Theodor Schwann & Matthias
Jakob Schleiden
2. Cells are the basic units of structure and function in living things
3. All cells are created through division of pre-existing cells - Barthelemy du Mortier
History of development of cell theory
Antonie van Leeuwenhoek 1632 - 1723 - began to build his own microscopes, built best
microscopes available anywhere at the time. First person to see bacteria, blood cells,
protists, algae etc.. ‘little animals’
Robert Hooke 1665 - Published a book micrographia - described slices of cork on
microscopes, reminded him of prison cells - used to name living cells.
Germ theory of disease - Koch’s postulates
Microorganism must be found in abundance in all organisms suffering from the disease, but
should not be found in healthy organisms.
Microorganism must be isolated from diseased organisms and grown in pure culture.
Cultured microorganisms should cause disease when introduced to a healthy organism.
Microorganisms must be reisolated from the inoculated, diseased experimental host and
identified as being identical to the original specific causative agent.
-
What are the Universal features of all cells?
- Evolution from a common ancestor
- All cells are surrounded by a plasma membrane
- Cells exchange molecules with their surroundings e.g: sugars, amino acids, ions, water
usually via transport proteins
- Cells communicate
- All cells store their genetic information as DNA
- Protein synthesis - cells translate RNA into protein in the same way
- Organelles of eukaryotic cells
- Life is a ‘pattern in a flux’ molecules are constantly being exchanged
- The DNA fragment corresponding to 1 protein is 1 gene
- Cells are made from a few simple building blocks
, What is Taxonomy ?
- The academic discipline of defining groups of biological organisms on a basis of shared
characteristics
- the branch of science concerned with classification, especially of organisms; systematics
What is Phylogenetics?
- study of evolutionary relationships among groups of organisms
What is Homeostasis?
- The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting
its physiological processes
- Almost all molecules in the human body are continuously replaced, exception: DNA
Lecture 2:
Biological Molecules:
What are biological molecules?
- Life is based on reactions between molecules
- Biological molecules are carbon based (except for some small inorganic molecules)
- Can be classified into a no of categories
A summary of biological molecules:
Small Large (macromolecules)
sugars polysaccharides
amino acids proteins
nucleotides nucleic acids (DNA, RNA)
lipids/fats associate to form membrane
Small molecules often play at least 2 roles, what are they?
- as building blocks for molecules
- as some other specific function in their own right
Composition of cell:
Proportion of total cell weight
Water 70
Inorganic ions 1
Small organic molecules 3
Macromolecules 26
