DNA 1.3- Proteins Flashcards
3.1 protein structure, 3.2 protein function, 3.3 enzymes
Describe the factors that determine the primary structure of proteins
Primary structure is a polypeptide chain of amino acids. The DNA sequence determines mRNA sequence which determines the amino acid sequence.
Describe the factors that determine the secondary structure of proteins
Secondary structure is the folding of a polypeptide chain due to hydrogen bonds forming an alpha helix or beta sheet.
Describe the factors that determine the tertiary structure of proteins
Tertiary structure is when amino acids form bonds, causing the polypeptide to fold into a 3D structure. The number, type, and sequence of amino acids determine the shape of the protein which determines function.
Describe the factors that determine the quaternary structure of proteins
Quaternary structure is when two or more polypeptide chains bind together; not all proteins have quaternary structure
Why is the three-dimensional shape of a protein critical to its function?
The three-dimensional shape of a protein is critical to its function because it determines how the protein interacts with other molecules in the cell.
How is the unique shape of a protein determined?
The unique shape of a protein is determined by the process of protein folding.
How do hormones function in the body, and why is their shape important?
Hormones function as chemical messengers by binding to specific receptors. Their shape is important because it allows them to bind to their receptors and initiate cellular responses. If their shape changes, they may lose the ability to bind to their receptors and lose their function.
What is the role of receptor proteins, and how does their shape influence their function?
Receptor proteins bind to specific messenger molecules, initiating cellular responses. Their shape is crucial because it determines their ability to bind to the messenger molecules. If their shape changes, they may not be able to bind to the messenger molecules and initiate the cellular response.
How do antibodies function in the immune system, and why is their shape important?
Antibodies recognize and bind to specific antigens, helping the immune system identify pathogens. Their shape is essential because it allows them to bind specifically to the complementary antigen. If their shape changes, they may not be able to recognize the antigen, potentially leading to infections or autoimmune diseases.
explain activation energy
Generally, chemical reactions will not start unless there is an input of energy. Biological enzymes have evolved by lowering the activation energy needed to start the process. This can be done by, bringing reactants together in the correct orientation, by binding to a substrate molecule that puts a strain on chemical bonds, or by making the reaction happen in small steps that only require small amounts of energy.
Describe the induced fit model of enzyme-substrate binding.
Substrate binds complementary to active site of enzyme. Shape of enzyme and substrate make a conformational change for induced fit. Bonds of substrate are strained. Products released and enzyme returns to original shape. Enzyme is reused.
