Unit 1: Cell And Cell Research Flashcards
Define a cell.
The cell is the basic structural, functional, and biological unit of all known organisms. The cell is the minimum unit of an capable of organism acting autonomously
What are the 4 rules of cell theory.
- All living organisms are composed of one or more cells.
- The cell is the basic unit of structure and organisation in organisms.
- Cells arise from pre-existing cells.
- Hereditary information (DNA) is passed on from cell to cell.
When was cell theory formulated?
1839
Who invented the first microscope and what did they see?
Antonie van Leeuwenhoek saw some cells (Protozoa, blood cells, sperm cells and bacteria)
When was Antonie van Leeuwenhoek alive?
1632-1723
Define prokaryotic cells.
Derived from the Greek “before the nucleus”. They comprise bacteria and archaebacteria and are small cells with simple structure. Absence of a nucleus so the genomes are less complex and do not contain cytoplasmic organelles or cytoskeleton.
Define eukaryotic cells.
Derived from the Greek “true nucleus” and make up all other living organisms including protozoa, fungi and animals. They are much bigger.
Spontaneous formation of organic molecules experiment.
Water vapour was expelled into an atmosphere made up of hydrogen (H2), methane (CH4) and ammonia (NH3) in which sparks were discharged. Analysis of the reaction products revealed the formation of several organic molecules.
Name some of the products.
Alanine, aspartic acid, glutamic acid and glycine.
Who carried out/discovered this experiment?
Stanley Miller
Formation of macromolecules
Monomers have been shown to spontaneously polymerise under plausible prebiotic conditions. E.g heating dry mixtures of amino acids results in polypeptides.
What is the fundamental characteristic of a macromolecule for life to evolve?
The ability to replace itself AKA the synthesis of new copies of itself.
**Only nucleic acids (DNA and RNA) are capable of directing their replication
RNA self replication
Complementary pairs between nucleotides ( adenine with uracil and guanine with cytosine) allow an RNA strand to serve as a template for the synthesis of a new strand with the complementary sequence. RNA is the only one capable of catalysing its own replication.
What is the central dogma of molecular biology?
How proteins are formed.
- DNA to RNA = transcription
- RNA to protein = translation
- RNA to DNA = reverse transcription (tRNA read rna to dna?)
How is the first cell believed to have arisen?
From the coating of self-replicating RNA and its associated molecules by a membrane composed of phospholipids.
What would the first cell have consisted of?
Self-replicating RNA and it’s encoded proteins.
What does each phospholipid molecule contain?
2 long hydrophobic tails attached to a hydrophilic head. The hydrophobic tails are embedded in the lipid bilayer; the hydrophilic heads are exposed to water on both sides of the membrane.
Generation of metabolic energy
- Glycolysis: glucose (C6H12O6)-> lactic acid (2 C3H6O3) and generates 2 ATP.
- Photosynthesis: 6 CO2 + 6 H2O -> C6H12O6 + 6 O2.
- Oxidative metabolism: C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O and generates 36-38 ATP.
What is glycolysis? (evolution of metabolism)
The anaerobic breakdown of glucose into lactic acid,.
What is photosynthesis? (evolution of metabolism)
Uses the energy from the sun to synthesise glucose from carbon dioxide and water, releasing oxygen ans a product. This O2 is used by oxidative metabolism.
