Unit 1 Flashcards
what is the proteome
the proteome is the entire set of proteins expressed by a genome
what factors affect the set of proteins expressed by a given cell type
metabolic activity of the cell, cellular stress, response to signalling molecules and healthy vs diseased cells
what is the difference between the two ERs
Rough endoplasmic reticulum has ribosomes on its cytosolic face whereas smooth endoplasmic reticulum lacks ribosomes
what is the Golgi apparatus
the Golgi apparatus is a series of connected flattened membrane discs to allow molecules to move within the apparatus. the Golgi apparatus is adjacent to the endoplasmic reticulum.
what are lysosomes
membrane bound organelles containing a variety of hydrolyses that digests proteins lipids, nucleic acids and carbohydrates. they are acid allowing optical function of its enzymes.
what is the site of lipid synthesis
smooth endoplasmic reticulum
where is the site of protein synthesis
the synthesis of all proteins start and end in the cytosolic ribosome then the proteins remain in the cytosol.
what are examples of post translational modification
proteolytic cleavage, phosphorylation and adding functional groups
what is the basic structure of amino acids
central carbon, amine (NH2), carboxylic acid (COOH), a hydrogen and a variable R group.
what are the features of an acidic amino acid
carboxylic acid (COOH) group, hydrophilic
what are the features of a basic amino acid
Amine group, hydrophilic
what are the features of a polar amino acid
C=O, OH or NH group, hydrophilic
what are the features of an hydrophobic amino acid
hydrocarbon group, hydrophobic
what causes the range of functions of amino acids
the R groups which vary in size, shape, charge, hydrogen bonding capacity and chemical reactivity.
what is the primary structure of a protein
the sequence in which the amino acids are synthesised into the polypeptide
what are the three types of tertiary structure
alpha helix, beta sheet and turns
which amino acid is the main driving force of protein folding
hydrophobic as hydrophilic predominate at the surface of a soluble protein
what bonds are found in proteins
hydrogen bond and disulphide bonds.
what is quaternary structure of proteins
protein with two or more connected polypeptide subunits.
what are the non protein binding units necessary for proteins function
prosthetic groups
what are allosteric proteins
allosteric proteins have quaternary structure and multiple binding sites, when a substrate binds to one of these sites the affinity of the others alters. this means activity of enzymes can vary greatly with small changes of substrate concentration
how does pH and temperature affect affinity
as temperature increases affinity decreases and as pH increases affinity increases
what do modulators do
modulators change the conformation of allosteric proteins. positive modulators increase affinity, negative modulators decrease affinity
what enzyme os responsible for the phosphorylation of proteins
kinase
what enzyme os responsible for the dephospho-rylation of proteins
phosphatase
what are the two membrane protein types
integral and peripheral
What are the specific sites on DNA that hormone response complexes bind to
hormone response elements, which directs influence the rate of transcription
what is the cytoskeleton
the network of proteins extending throughout the cytoplasm is known as the cytoskeleton
what protein are microtubules composed of?
tubulin radiations from the centrosome
what does the cell cycle compose of
G1 phase DNA synthesis, S phase DNA Replication, M phase and G2 phase further DNA growth
what are the stages of mitosis
interphase, prophase, metaphase, anaphase, telophase
what protein is involved in regulating the cell cycle
cyclin with combine to cyclin dependent kinases to phosphorylate proteins that regulate progression through the cycle
what is the result of uncontrolled reduction in the rate of the cell cycle
degenerative disease
what is the result of an uncontrolled increase in the rate of the cell cycle
tumour formation
what is apoptosis and how is it brought upon
triggered by internal or external death signals such as DNA damage from lymphocytes.
death signals bring upon activation of caspases that cause destruction of the cell
what does an internal death signal resulting from DNA damage do
activates p53 tumour suppressor protein
Name the class of enzyme found within lysosomes.
hydrolase
Describe the role of vesicles.
Transport materials between membrane compartments.
Define the term facilitated diffusion.
The passive transport of substances across the membrane through specific transmembrane proteins.
Describe the relationship between the sodium-potassium pump and glucose symport in the small intestine.
The sodium gradient created by the sodium-potassium pump drives the active transport of glucose.
What type of protein are the receptors for steroid hormones?
Transcription factors
What is an action potential?
A wave of electrical excitation along a neuron’s plasma membrane.
Describe the role of CDKs.
They phosphorylate proteins that regulate progression through the cycle.
Describe one role of p53 protein.
stimulate DNA repair;
stop/arrest the cell cycle;
cause cell death/apoptosis
Give an example of an internal death signal.
DNA damage
Give an example of an external death signal.
lymphocytes
What term described the pH at which a soluble protein had no net charge and will precipitate out of solution
Isoelectric point
What is a haemocytometer used for
To estimate cell numbers in a liquid culture
Describe the cause of type 2 diabetes
Loss of insulin receptor function
