cell composition and science M1V1 Flashcards
what is a cell
- the smallest possible living, self containing unit
- organelles IN cytosol SURROUNDED by a membrane
- carries out all of life’s functions
- they are tiny, and we have many
what are cells measured in
microns (1/1000th of a millimetre)
what are molecules measured in
nanometres (1/100th of a mircron)
light microscope
- used to see whole cells/ live tissue in colour
transmission electron microscope
- bigger magnification
- used to see intracellular organelles and membranes / dead tissue in black and white
scanning electrons microscope
like TEM but 3D
what do all cells have in common
- plasma membrane
- chromosomes (DNA)
- Cytosol
- ribosomes
prokaryotes
- cells that dont have membrane bound nuclei and organelles
- include the domain bacteria
eukaryotes
- cells that have membrane bound their nuclei and organelles
- includes the domain Eukarya (which includes many Kingdoms, including animals and plants)
germ theory
- many diseases caused by microorganisms in the body
- straight neck flash caused sterile broth to become contaminated
- crooked neck flask (ie no bacteria could get into the broth) caused broth to remain sterile
pasteurs challenge and fermentation - he tested four theories
he tested four theories
- fermentation occurred spontaneously - he sealed a flask of sterile grape juice, and it didn’t ferment (rejected)
- air fermented the juice - had a curved neck to allow air access but stop microbes, no fermentation (rejected)
- bacteria ferment into alcohol - innoculated with bacteria and sealed, but fermentation into acid occurs (change)
- yeasts ferment it into alcohol - innoculated with yeast, sealed, alcohol produced (accepted)
kochs postulates - 4 criteria
- organism present in every case of disease
- organism must be isolated from host with disease and grown in pure culture
- specific disease reproduced when pure culture of that organism is put into a healthy host
- organism must be recoverable from said host after the disease develops
all 4 of these must be met to prove that disease is caused by a particular microorganism
cell composition
- the human body is mostly oxygen, with carbon, hydrogen and nitrogen abundant as well
- these 4 elements combine to make the simple building blocks essential to all functions of cells and the body
what are the important parts that are key to a cells role
macromolecules, they are bio-polymers formed by lots of repeating units
what are the building block (repeating units) for these bio-molecules
- Protein
- Deoxyribonucleic acid (DNA)
- Ribonucleic acid (RNA)
- Polysaccharide (glycogen)
- Lipids
- amino acids
- deoxyriboncleotides
- Ribonucleotides
- Monosaccharides (glucose)
- fatty acids, glycerol
carbohydrates
help in cell recognition, energy and structure
- Monosaccharides (building blocks) form disaccharides (2), oligosaccharides ( a few) and polysaccharides (many) which link together to form carbohydrates
glucose
is a monosaccharide, and can exist in alpha and beta forms
lipids
- NOT polymers but come in lots of different forms
- Hydrophobic (repels water)
function of lipids
- Membrane structure (cholesterol and phospholipids)
- Regulation
- Energy
nucleic acids
- A ribose sugar combines with a phosphate and a base to form a nucleotide
- bases include thymine, adenine, cytosine, guanine and uracil
- nucleic acids are polymers of nucleotides
- they include DNA and RNA
- Informational molecules
proteins
- polymers of the 20 different amino acids
- 100,000 unique proteins in the body
- genes give rise to proteins (covered later) - can give rise to just one or several
function of protein
they perform almost every function there is
how are proteins structured
proteins are formed by amino acids combine a long line called a peptide chain and then they form into a structure called a protein
