Topic 2.4: Protein Flashcards
What is the basic structure of an amino acid
An amine group
A carboxylic acid group
A hydrogen atom
A variable side chain (R)
How are amino acids joined
Through condensation reactions to form a dipeptide and water
What is the covalent bond between an amino acid
A peptide bond
Long chains of covalently bonded amino acids are called polypeptides
How are polypeptide chains broken down
Through hydrolysis reactions which requires water to reverse the process
How are peptide bonds formed
when the amine group loses the hydrogen (H) atom and the carboxylic acid loses a hydroxyl (OH), forming water
What are the four structures of proteins, the way amino acids fold
Primary structure
Secondary structure
Tertiary structure
Quaternary structure
What is denaturation
a structural change in a protein that results in the loss of its biological properties
What are the two conditions at which a protein denatures
temperature and pH
How does temperature affect a protein
High levels of temp. disrupt the hydrogen bonds that hold the protein together
when these bonds are broken, they will unfold and lose their capacity to function
How does pH affect a protein
amino acids are neutral molecules that possess both negative and positive charged regions
when the pH is changed, it alters the charge of the protein, changing its solubility and shape
What is a gene
a sequence of DNA that encodes a polypeptide sequence
What are the two processes to convert a gene sequence
Transcription, making mRNA based off of a DNA template
Translation, using instructions of MRNa transcript to link amino acids together
What is a proteome
a totality of proteins expressed in a cell, tissue, or organism
a proteome is unique, as protein expression patterns are determined by an individuals genes
what are the different roles of proteins in a cell
structure: collagen, spider silk
hormones: insulin, glucagon
immunity: immunoglobulins
transport: hemoglobin
sensation: rhodopsin
movement: actin, myosin
enzymes: rubisco, catalase
What is collagen
a component of the connective tissue of animals
What is spider silk
a fiber spun by spiders and used to make webs
What is insulin
protein produced by the pancreas and triggers a reductio in blood glucose levels
What is glucagon
protein produced by the pancreas that triggers an increase in blood glucose levels
What is immunoglobulins
antibodies produced by plasma cells that are capable of targeting specific antigens
What is hemoglobin
a protein found in red blood cells that is responsible for the transport of oxygen
What is cytochrome
a group of proteins located in the mitochondria and involved in the electron transport chain
What is rhodopsin
a pigment in the photoreceptor cells of the retina that is responsible for the detection of light
What is actin
thin filaments involved in the contraction of muscle fibres
What is myosin
thick filaments involved in the contraction of muscle fibres
