1.3 structure and function of proteins Flashcards
(18 cards)
what is the sequence of amino acids determined by?
The folding of a polypeptide to form a protein with a unique three dimensional shape.
what are the factors that determine the primary, secondary, tertiary and quartenary structure of proteins?
Primary Structure: The sequence of amino acids in a polypeptide chain.
Secondary Structure: The coiling (alpha helix) or folding (beta - pleated sheet) of amino acid chains due to hydrogen bonding between amino acids.
Tertiary Structure: 3D shape caused by the way its folded.
Quaternary: When proteins have more than one polypeptide chain. This is caused by chemical bonding between two chains.
what are proteins essential for?
cell structure and function.
what are some examples of proteins with specific shapes?
Enzymes, some hormones, Receptor proteins and antibodies.
Why is the three-dimensional structure of a protein critical to its function?
this shape determines which molecules it can interact with and how it can perform its biological roles.
what are receptor proteins?
proteins embedded in cell membrane that detect molecules eg. hormones that then stimulate a message or signal cell in some way
what are regulatory proteins?
they regulate gene expression and can ‘switch on’ or ‘switch off’ genes. There proteins can bind to and block or promote the transcription process.
what is proteomics?
the study of proteins.
what does the Enzyme do?
Enzymes have an active site where a substrate binds to. The enzyme is involved in speeding up the rate of a reaction.
what are antibodies?
B lymphocytes produce antibodies as an immune response. These antibodies then bind to antigens (foreign to the body) and deactivate them.
How is the three-dimensional shape of a protein determined?
The three-dimensional shape of a protein is determined by its sequence of amino acids, which dictates how the polypeptide folds.
What determines the primary structure of a protein?
The primary structure of a protein is determined by the sequence of amino acids in the polypeptide chain.
What factors contribute to the secondary structure of a protein?
The secondary structure is formed by hydrogen bonds between the amino acids, leading to structures like alpha helices and beta-pleated sheets.
What determines the tertiary structure of a protein?
The tertiary structure is determined by interactions between the side chains (R groups) of the amino acids, including hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges.
What factors determine the quaternary structure of a protein?
The quaternary structure is formed when two or more polypeptide chains (subunits) come together, stabilized by the same types of interactions seen in tertiary structure.
Why are proteins essential to cell structure and function?
Proteins are crucial because they perform a wide variety of functions, including catalyzing reactions (enzymes), providing structural support, regulating cellular processes, and transporting molecules.
What are some examples of proteins with specific shapes?
Examples include enzymes, hormones, receptor proteins, and antibodies, each with a unique shape suited to its function.
Why is the three-dimensional structure of a protein critical to its function?
The three-dimensional structure of a protein is critical because it determines the protein’s ability to bind to other molecules, catalyze reactions, and interact with its environment. A change in shape can alter or destroy its function.
