E1+ E2 Flashcards
What is cytosol
Represent the water containing inorganic ions and small organic molecules
Accounts for about 70-80% of the weight of a living cell
What is cytoplasm
A semi solid fluid that typically defines all contents
The nucleus
DNA packed into chromosomes within a nuclear matrix ( most cells are diploid)
Surrounded by a double membrane
Has nuclear pores to help movement of small molecules
Endoplasmic reticulum
Network of membrane folds with interconnected lumen
Rough er has ribosomes attached while smooth ER does not have
Serves as a store of ca2+ specially in muscle cells
Involves synthesis of lipids and steroids and detoxification of drugs in liver cell
Golgi apparatus
Stacks of flattened smooth membrane sacs and vesicles
Processing and sorting of cytoplasmic membrane proteins and secretory proteins
Proteins undergo post translational modification
Mitochondria
Main energy factory and source of atp
Double membrane structure
Has its own circular DNA , RNA AND Ribosomes
Vesicles
Lysosomes
Endosomes
Phagosomes
Peroxisomes
Ribosomes
Site of protein synthesis
Subunits : eukaryotes 80s (60s and 20s) prokaryotes 70s (50s and 30s)
Ribosomes
Site of protein synthesis
Subunits : eukaryotes 80s (60s and 20s) prokaryotes 70s (50s and 30s)
Cytoskeleton
Composed of distinct filamentous proteins that provide an internal scaffold contributing to cell shape and movement
Types of cytoskeleton
Microfilaments
Intermediate filaments
Microtubles
Prokaryotes
Have free DNA (Nucleoid)
Smaller ribosomes
Lack membrane bound organelles
Have cell wall
Viruses
Grouped with micro organisms
Very small and requires a host to live in
Need to infect a cell and use its machinery to reproduce
Can be double stranded or single stranded
Anatomy of virus
Capsid protects viral genome
Capsomers protect genetic material
Capsomers bind specific receptors to host cells surface
Naked viruses
Capsid only
Includes polio and hepatitis A
Enveloped viruses
Capsid surrounded by lipid Bilayer
Envelope contain viral protein for infecting specific cell types
Includes HIV and influenza A and B
Describe an amino acid molecule
Have a central carbon atom with 4 groups attached to it
Amino group NH3
Carboxyl group (COOH)
Hydrogen atom
And a variable R ( could be a group or a side chain)
Enantiomers
Has a chiral centre
Distinguished by optical rotation
Types of enantiomers
Levortatory (L) only in human cells
Dextrorotatory (D) are rare in nature but seen in bacterial cells wall and some antibiotics
Hydrophilic amino acids
Basic ( positive, amino acid group)
Acidic ( negative , carboxyl groups )
Polar ( uncharged at neutral ph , negative and positive charges balance )
How are amino acids linked together
In a linear sequence by peptide covalent bonds between Alpha amino and alpha carboxyl
Peptide bond
Has a partial double bond character as it’s rigid and planar
Primary structures
Linear sequence of amino acids
Includes location of other covalent bonds like disulphide
Secondary structures
Local shape of polypeptide chain maintained by hydrogen bonds
Alpha helix’s or beta pleated sheets
Tertiary structures
Over 3d shape arrangement
Binding of prosthetic groups
Quaternary structures
Association of 2 or more polypeptide chains into a multi subunit complex
How is the stability of a protein maintained
By a combination of non covalent interactions
Globular proteins
Compact structures
Soluble in aqueous environments
Includes haemoglobin and various enzymes
Fibrous proteins
Long structures
Insoluble in aqueous environment
Includes keratin, collagen and elastin
