introduction to cell Flashcards
what book did robert hooke write
micrograpgia
hooke famous for
comparing monks cells to cork cell –> responsible for giving the name cell to cell
antony van leeuwenhoek
discovered bacteria, free living persistc microscopic protists, sperm cells and muscle fbres
basic features of the cell
1) all cells come from pre-existing cells by division
2) cells contain hereditary info which is passed on
3) all cells are basically the same chemical composition
4) all energy flow of life occurs within cells
cell theory by matthias schlseiden and theodor schwann
1) cell is the unit structure, physiology and organisation in living things
2) the cll retains a duel existence as a distinct entity and a building block in the construction of organisms
3) cells form by free-cell formation similar to formation of crystal (spontaneous generation)
which part of schleidens and schwas theory was wrong
spontaneous generation
rudolph virchow
all cells arise from pre-existing cells
cells are very small
a pearl string of 20,000,000 ribosomes makes 1 metern
mitochondria bigger than ribosomes
yes
virus bigger than haemoglobubulin
yes
how many cells in the human body
10^14
common features of all cells
1) cell gather material from the environment and duplicate
2)info is stored and inherited by DNA
3)info is partially transcribed into an intermediate form (RNA)
4)RNA serves for construction of proteins (translation)
5)proteins ar molecules that put genetic info into action
60all cells are enclosed by a plasma membrane which material must pass
5 kingdoms classification of life
plantae fungi animalia protsig prokaryoten(monera)
three domain classification life
archaea
eukaryotic cells
prokaryotic cells
carl woese
introduced archaea
eukaryotic cells do not have
a cell wall or any chloroplasts
differences between five kingdoms
animal and protozoa are only cells without cell wall and plant cells are the only ones with chloroplasts. Fonera have free DNA in the form of a plasmid
when was the solar system formed
4.5 million ya
between 4 and 3.5 billion years ago..
development of first cell
3 billion ya
phosyntheis developed in cyanobacteria, therefore must have been oxygen in atmosphere
homo sapiens developed
around 0.4-0.25 may
prostista
kingdom that comprises mostly of single celled organisms such as protozoa and simple algae
monera
taxonomic kingdom which included prokaryotic organisms, which are organism which don’t have a nucleus.
how ar organic molecules thought to have been formed
atmospheric conditions e.g. formaldehyde from the air due to lightening and sugars from water reservoirs
charles darwin
‘But if we could conceive in some warm little pond with all sorts of ammonia and phosphoric salts, heat, electricity present, that a protein compound was chemically formed, ready to undergo still more complex changes’
francis cricks central dogma
3 molecules interact to pass on detailed info
DNA–> transcription –> RNA –> translation–> protein
RNA and enzymatic activity
single stranded ran can fold and form molecules that catalyse chemical reactions
a catalytic ran molecule is called a
ribozyme rRNA
riboeznymes consists of
proteins and RNA a
–> ribosomes translate mRNA into proteins
enzymatic activity of ribsosomes depends
on the RNA part of the ribosome
RNA world hypothesis
RNA was at the origin of life–> stored genetic info and catalysed chemical reactions
proof of RNA hypothesis
building blocks of RNA can be formed under ‘early earth’ conditions
ribonucleotides can be formed from
–> reactive cyanide, cyanoacetylene, glycoaldehyde, glyceraldehyde and inorganic phosphate
replicase
an enzyme which catalyses the synthesis of a complementary RNA molecule using an RNA template.
replicase ribozymes could produce new replicases
step 1: the ribozyme replicase an unfolded RNA strand of another replicase molecule
step 2: at high temperature, both trans separate, one fold into a new replicase, one serves as a template for further synthesis
on clay surfaces
RNA chains can spontaneously polymerise
monera and archaea do not have
an endomembrane system
