Proteins Flashcards
The shape of a protein molecule directly determines…. what?
its function
What are the four levels that describe the primary structure of proteins?
The primary structure The secondary structure The tertiary structure The quaternary structure
What are proteins?
the most abundant organic molecules in the body and have the widest variety of functions
What are proteins used for?
- cell structures and structural body tissues - for controlling chemical reactions - for regulating growth - for defending the body from invaders - catalyze or speed up all reactions occurring in the body - they transport ions and other molecules into and out of the body - can think of them as worker molecules of the body that organize and facilitate all metabolic processes
Proteins are organic molecules, what are they made of?
mostly carbon, oxygen, hydrogen, and nitrogen Some contain sulfur, iron, or phosphorus
Proteins are organic molecules, what are they made of?
mostly carbon, oxygen, hydrogen, and nitrogen Some contain sulfur, iron, or phosphorus
What are the building blocks of protein?
amino acids - linked together
What makes each protein unique and defines the function of the protein?
the sequence of the amino acids
How many different amino acids are used in the body?
20 and they all share the same basic structure
What does the amino acid contain?
- a central carbon atom attached to a hydrogen atom - an amino group (NH₂) - a carboxyl group (COOH) - a unique group of atoms called a side chain designated by the letter R (defines each amino acid) (the side chain can be simple or complex)
What does the amino acid contain?
- a central carbon atom attached to a hydrogen atom - an amino group (NH₂) - a carboxyl group (COOH) - a unique group of atoms called a side chain designated by the letter R (defines each amino acid)
Amino acids can be linked together in how many combinations to form proteins?
an infinite variety
What determines the nature and function of the resultant protein?
the specific combination of amino acids as ordered by the cell’s DNA
A bond between one amino acids is what type of bond?
a peptide bond Example: a carboxyl group of one amino acid links with the amino group of another amino acid
What is a dipeptide bond?
a short chain of two amino acids
What is a tripeptide bond?
a chain of three amino acids linked together
What is it called when the amino acid chain exceeds 100 amino acids?
a protein
What is the secondary structure of a protein?
the natural bend of parts of the peptide chain as it is formed in three dimensions
When are the bends stabilized in the secondary structure of a protein?
when the atoms of the protein molecule form weak hydrogen bonds with each other or dehydration synthesis (can be either helical(spiral) or pleated)
When are the bends stabilized in the secondary structure of a protein?
when the atoms of the protein molecule form weak hydrogen bonds with each other (can be either helical(spiral) or pleated)
What is the tertiary structure?
the overall shape of a single protein molecule
What kind of bond occurs when there is a chain of three amino acids linked together?
a tripeptide bond
What are structural proteins?
stable, rigid, water-insoluable proteins that are used for adding strength to tissues or cells often call fibrous proteins (because of their long, stringy shape) Examples: collagen - located in the main protein in connective tissues like ligaments, cartilage, bone, and tendons, fibrin, and keatin
What are functional proteins?
generally water-soluble and have a flexible, three-dimensional shape, which can change under different circumstances
