1.6: Proteins Flashcards
Proteins are usually what molecules?
Proteins are usually very large molecules
Proteins are usually very large molecules.
The types of carbohydrates and lipids in all organisms are what?
The types of carbohydrates and lipids in all organisms are:
- Relatively few
- Very similar
Proteins are usually very large molecules.
The types of carbohydrates and lipids in all organisms are relatively few and they are very similar.
However, each organism has numerous proteins that do what?
Each organism has numerous proteins that differ from:
- Species
to
- Species
Proteins are usually very large molecules.
The types of carbohydrates and lipids in all organisms are relatively few and they are very similar.
However, each organism has numerous proteins that differ from species to species.
The shape of any one type of protein molecule differs from what?
The shape of any one type of protein molecule differs from that of all other types of proteins
Proteins are usually very large molecules.
The types of carbohydrates and lipids in all organisms are relatively few and they are very similar.
However, each organism has numerous proteins that differ from species to species.
The shape of any one type of protein molecule differs from that of all other types of proteins.
Proteins are very important molecules in living organisms.
Indeed the word ‘protein’ is a Greek work meaning what?
Indeed the word ‘protein’ is a Greek work meaning ‘of first importance’
Proteins are usually very large molecules.
The types of carbohydrates and lipids in all organisms are relatively few and they are very similar.
However, each organism has numerous proteins that differ from species to species.
The shape of any one type of protein molecule differs from that of all other types of proteins.
Proteins are very important molecules in living organisms.
Indeed the word ‘protein’ is a Greek work meaning ‘of first importance.’
One group of proteins, what, is involved in almost every what?
One group of proteins, enzymes, is involved in almost every living process
Proteins are usually very large molecules.
The types of carbohydrates and lipids in all organisms are relatively few and they are very similar.
However, each organism has numerous proteins that differ from species to species.
The shape of any one type of protein molecule differs from that of all other types of proteins.
Proteins are very important molecules in living organisms.
Indeed the word ‘protein’ is a Greek work meaning ‘of first importance.’
One group of proteins, enzymes, is involved in almost every living process.
There is a vast range of different enzymes that between them do what?
There is a vast range of different enzymes that between them perform a very diverse number of functions
The structure of an amino acid:
What are amino acids?
Amino acids are the basic monomer units that combine to make up a polymer called a polypeptide
The structure of an amino acid:
Amino acids are the basic monomer units that combine to make up a polymer called a polypeptide.
Polypeptides can be combined to do what?
Polypeptides can be combined to form proteins
The structure of an amino acid:
Amino acids are the basic monomer units that combine to make up a polymer called a polypeptide.
Polypeptides can be combined to form proteins.
How many amino acids have been identified?
About 100 amino acids have been identified
The structure of an amino acid:
Amino acids are the basic monomer units that combine to make up a polymer called a polypeptide.
Polypeptides can be combined to form proteins.
About 100 amino acids have been identified, of which how many occur naturally where?
About 100 amino acids have been identified, of which 20 occur naturally in proteins
The structure of an amino acid:
Amino acids are the basic monomer units that combine to make up a polymer called a polypeptide.
Polypeptides can be combined to form proteins.
About 100 amino acids have been identified, of which 20 occur naturally in proteins.
The fact that the same 20 amino acids occur in all living organisms provides what?
The fact that the same 20 amino acids occur in all living organisms provides indirect evidence for evolution
The structure of an amino acid:
Every amino acid has a what?
Every amino acid has a central carbon atom
The structure of an amino acid:
Every amino acid has a central carbon atom to which are attached what?
Every amino acid has a central carbon atom to which are attached 4 different chemical groups:
- The amino group
- The carboxyl group
- A hydrogen atom
- R (side) group
The structure of an amino acid:
Every amino acid has a central carbon atom to which are attached 4 different chemical groups - the amino group, the carboxyl group, a hydrogen atom and the R (side) group.
The amino group is -what?
The amino group is -NH2
The structure of an amino acid:
Every amino acid has a central carbon atom to which are attached 4 different chemical groups - the amino group, the carboxyl group, a hydrogen atom and the R (side) group.
The amino group is -NH2.
The amino group is a basic group from which what is derived?
The amino group is a basic group from which the ‘amino’ part of the name amino acid is derived
The structure of an amino acid:
Every amino acid has a central carbon atom to which are attached 4 different chemical groups - the amino group, the carboxyl group, a hydrogen atom and the R (side) group.
The carboxyl group is -what?
The carboxyl group is -COOH
The structure of an amino acid:
Every amino acid has a central carbon atom to which are attached 4 different chemical groups - the amino group, the carboxyl group, a hydrogen atom and the R (side) group.
The carboxyl group is -COOH.
The carboxyl group is a what group which gives what?
The carboxyl group is an acidic group which gives the amino acid the ‘acid’ part of its name
The structure of an amino acid:
Every amino acid has a central carbon atom to which are attached 4 different chemical groups - the amino group, the carboxyl group, a hydrogen atom and the R (side) group.
The hydrogen atom is -what?
The hydrogen atom is -H
The structure of an amino acid:
Every amino acid has a central carbon atom to which are attached 4 different chemical groups - the amino group, the carboxyl group, a hydrogen atom and the R (side) group.
What is the R (side) group?
The R (side) group is a variety of different chemical groups
The structure of an amino acid:
Every amino acid has a central carbon atom to which are attached 4 different chemical groups - the amino group, the carboxyl group, a hydrogen atom and the R (side) group.
The R (side) group is a variety of different chemical groups.
Each amino acid has a different what?
Each amino acid has a different R group
The structure of an amino acid:
Every amino acid has a central carbon atom to which are attached 4 different chemical groups - the amino group, the carboxyl group, a hydrogen atom and the R (side) group.
The R (side) group is a variety of different chemical groups.
Each amino acid has a different R group.
The 20 naturally occurring amino acids differ only in their what?
The 20 naturally occurring amino acids differ only in their R (side) group
The formation of a peptide bond:
In a similar way that monosaccharide monomers combine to form disaccharides, amino acid monomers can combine to form what?
In a similar way that monosaccharide monomers combine to form disaccharides:
- Amino acid monomers
can combine to form
- A dipeptide
The formation of a peptide bond:
In a similar way that monosaccharide monomers combine to form disaccharides, amino acid monomers can combine to form a dipeptide.
The process is essentially the same - the what in a what reaction?
The process is essentially the same - the removal of a water molecule in a condensation reaction
The formation of a peptide bond:
In a similar way that monosaccharide monomers combine to form disaccharides, amino acid monomers can combine to form a dipeptide.
The process is essentially the same - the removal of a water molecule in a condensation reaction.
The water is made by doing what?
The water is made by combining a:
- -OH from the carboxyl group of one amino acid
with
- -H from the amino group of another amino acid
The formation of a peptide bond:
In a similar way that monosaccharide monomers combine to form disaccharides, amino acid monomers can combine to form a dipeptide.
The process is essentially the same - the removal of a water molecule in a condensation reaction.
The water is made by combining a -OH from the carboxyl group of one amino acid with a -H from the amino group of another amino acid.
The 2 amino acids then become what?
The 2 amino acids then become linked
The formation of a peptide bond:
In a similar way that monosaccharide monomers combine to form disaccharides, amino acid monomers can combine to form a dipeptide.
The process is essentially the same - the removal of a water molecule in a condensation reaction.
The water is made by combining a -OH from the carboxyl group of one amino acid with a -H from the amino group of another amino acid.
The 2 amino acids then become linked by what?
The 2 amino acids then become linked by a new peptide bond
The formation of a peptide bond:
In a similar way that monosaccharide monomers combine to form disaccharides, amino acid monomers can combine to form a dipeptide.
The process is essentially the same - the removal of a water molecule in a condensation reaction.
The water is made by combining a -OH from the carboxyl group of one amino acid with a -H from the amino group of another amino acid.
The 2 amino acids then become linked by a new peptide bond between what?
The 2 amino acids then become linked by a new peptide bond between the:
- Carbon atom of one amino acid
- Nitrogen atom of the other
The formation of a peptide bond:
In a similar way that monosaccharide monomers combine to form disaccharides, amino acid monomers can combine to form a dipeptide.
The process is essentially the same - the removal of a water molecule in a condensation reaction.
The water is made by combining a -OH from the carboxyl group of one amino acid with a -H from the amino group of another amino acid.
The 2 amino acids then become linked by a new peptide bond between the carbon atom of one amino acid and the nitrogen atom of the other.
In a similar way as a glycosidic bond of a disaccharide can be broken by the addition of water (hydrolysis), the peptide bond of a dipeptide can also be broken by what?
In a similar way as a glycosidic bond of a disaccharide can be broken by the addition of water (hydrolysis), the peptide bond of a dipeptide can also be broken by hydrolysis
The formation of a peptide bond:
In a similar way that monosaccharide monomers combine to form disaccharides, amino acid monomers can combine to form a dipeptide.
The process is essentially the same - the removal of a water molecule in a condensation reaction.
The water is made by combining a -OH from the carboxyl group of one amino acid with a -H from the amino group of another amino acid.
The 2 amino acids then become linked by a new peptide bond between the carbon atom of one amino acid and the nitrogen atom of the other.
In a similar way as a glycosidic bond of a disaccharide can be broken by the addition of water (hydrolysis), the peptide bond of a dipeptide can also be broken by hydrolysis to give what?
In a similar way as a glycosidic bond of a disaccharide can be broken by the addition of water (hydrolysis), the peptide bond of a dipeptide can also be broken by hydrolysis to give its 2 constituent amino acids
The primary structure of proteins - polypeptides:
Through a series of what, many amino acid monomers can be joined together in a process called what?
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation
The primary structure of proteins - polypeptides:
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation.
What is a polypeptide?
A polypeptide is the resulting chain of many hundreds of amino acids
The primary structure of proteins - polypeptides:
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation.
A polypeptide is the resulting chain of many hundreds of amino acids.
What forms the primary structure of any protein?
The sequence of amino acids in a polypeptide chain forms the primary structure of any protein
The primary structure of proteins - polypeptides:
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation.
A polypeptide is the resulting chain of many hundreds of amino acids.
The sequence of amino acids in a polypeptide chain forms the primary structure of any protein.
This sequence is determined by what?
This sequence of amino acids in a polypeptide chain is determined by DNA
Polypeptides have many (usually how many) of the what joined in different sequences?
Polypeptides have many (usually hundreds) of the 20 naturally occurring amino acids joined in different sequences
The primary structure of proteins - polypeptides:
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation.
A polypeptide is the resulting chain of many hundreds of amino acids.
The sequence of amino acids in a polypeptide chain forms the primary structure of any protein.
This sequence is determined by DNA.
As polypeptides have many (usually hundreds) of the 20 naturally occurring amino acids joined in different sequences, it follows that there is an almost limitless number of possible what?
As polypeptides have many (usually hundreds) of the 20 naturally occurring amino acids joined in different sequences, it follows that there is an almost limitless number of possible:
- Combinations
- Therefore types of primary protein structure
The primary structure of proteins - polypeptides:
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation.
A polypeptide is the resulting chain of many hundreds of amino acids.
The sequence of amino acids in a polypeptide chain forms the primary structure of any protein.
This sequence is determined by DNA.
As polypeptides have many (usually hundreds) of the 20 naturally occurring amino acids joined in different sequences, it follows that there is an almost limitless number of possible combinations and therefore types of primary protein structure.
It is the primary structure of a protein that determines its what?
It is the primary structure of a protein that determines its:
- Shape
- Therefore its function
The primary structure of proteins - polypeptides:
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation.
A polypeptide is the resulting chain of many hundreds of amino acids.
The sequence of amino acids in a polypeptide chain forms the primary structure of any protein.
This sequence is determined by DNA.
As polypeptides have many (usually hundreds) of the 20 naturally occurring amino acids joined in different sequences, it follows that there is an almost limitless number of possible combinations and therefore types of primary protein structure.
It is the primary structure of a protein that determines its shape and therefore its function.
A change in just what can lead to a change in what?
A change in just a single amino acid in this primary sequence can lead to a change in the shape of the protein
The primary structure of proteins - polypeptides:
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation.
A polypeptide is the resulting chain of many hundreds of amino acids.
The sequence of amino acids in a polypeptide chain forms the primary structure of any protein.
This sequence is determined by DNA.
As polypeptides have many (usually hundreds) of the 20 naturally occurring amino acids joined in different sequences, it follows that there is an almost limitless number of possible combinations and therefore types of primary protein structure.
It is the primary structure of a protein that determines its shape and therefore its function.
A change in just a single amino acid in this primary sequence can lead to a change in the shape of the protein and may stop what?
A change in just a single amino acid in this primary sequence:
- Can lead to a change in the shape of the protein
- May stop it carrying out its function
The primary structure of proteins - polypeptides:
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation.
A polypeptide is the resulting chain of many hundreds of amino acids.
The sequence of amino acids in a polypeptide chain forms the primary structure of any protein.
This sequence is determined by DNA.
As polypeptides have many (usually hundreds) of the 20 naturally occurring amino acids joined in different sequences, it follows that there is an almost limitless number of possible combinations and therefore types of primary protein structure.
It is the primary structure of a protein that determines its shape and therefore its function.
A change in just a single amino acid in this primary sequence can lead to a change in the shape of the protein and may stop it carrying out its function.
Change its shape and it will do what?
Change its shape and it will function:
- Less well
Or,
- Differently
The primary structure of proteins - polypeptides:
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation.
A polypeptide is the resulting chain of many hundreds of amino acids.
The sequence of amino acids in a polypeptide chain forms the primary structure of any protein.
This sequence is determined by DNA.
As polypeptides have many (usually hundreds) of the 20 naturally occurring amino acids joined in different sequences, it follows that there is an almost limitless number of possible combinations and therefore types of primary protein structure.
It is the primary structure of a protein that determines its shape and therefore its function.
A change in just a single amino acid in this primary sequence can lead to a change in the shape of the protein and may stop it carrying out its function.
Change its shape and it will function less well or differently.
A simple protein may consist of what?
A simple protein may consist of a single polypeptide chain
The primary structure of proteins - polypeptides:
Through a series of condensation reactions, many amino acid monomers can be joined together in a process called polymerisation.
A polypeptide is the resulting chain of many hundreds of amino acids.
The sequence of amino acids in a polypeptide chain forms the primary structure of any protein.
This sequence is determined by DNA.
As polypeptides have many (usually hundreds) of the 20 naturally occurring amino acids joined in different sequences, it follows that there is an almost limitless number of possible combinations and therefore types of primary protein structure.
It is the primary structure of a protein that determines its shape and therefore its function.
A change in just a single amino acid in this primary sequence can lead to a change in the shape of the protein and may stop it carrying out its function.
Change its shape and it will function less well or differently.
A simple protein may consist of a single polypeptide chain.
More commonly, however, a protein is made up of what?
More commonly, however, a protein is made up of a number of polypeptide chains
The secondary structure of proteins:
The linked amino acids that make up a polypeptide possess both what groups?
The linked amino acids that make up a polypeptide possess both:
- -NH
- -C = O
groups
The secondary structure of proteins:
The linked amino acids that make up a polypeptide possess both -NH and -C = O groups where?
The linked amino acids that make up a polypeptide possess both:
- -NH
- -C = O
groups on either side of every peptide bond
The secondary structure of proteins:
The linked amino acids that make up a polypeptide possess both -NH and -C = O groups on either side of every peptide bond.
What has an overall positive charge?
The H of the -NH group has an overall positive charge
The secondary structure of proteins:
The linked amino acids that make up a polypeptide possess both -NH and -C = O groups on either side of every peptide bond.
The H of the -NH group has an overall positive charge, while what has overall negative charge?
The:
- H of the -NH group has an overall positive charge
,while
- O of the -C = O group has an overall negative charge
The secondary structure of proteins:
The linked amino acids that make up a polypeptide possess both -NH and -C = O groups on either side of every peptide bond.
The H of the -NH group has an overall positive charge, while the O of the -C = O group has an overall negative charge.
These 2 groups therefore do what?
These 2 groups therefore readily form weak bonds
The secondary structure of proteins:
The linked amino acids that make up a polypeptide possess both -NH and -C = O groups on either side of every peptide bond.
The H of the -NH group has an overall positive charge, while the O of the -C = O group has an overall negative charge.
These 2 groups therefore readily form weak bonds, called hydrogen bonds.
This causes the long polypeptide chain to be twisted into a 3-D shape, such as what?
This causes the long polypeptide chain to be twisted into a 3-D shape, such as the coil known as an a-helix
The tertiary structure of proteins:
The a-helices of the secondary protein structure can be what to give what?
The a-helices of the secondary protein structure can be:
- Twisted
- Folded even more
to give the 3-D structure of each protein
The primary structure of a protein
The primary structure of a protein is the sequence of amino acids found in its polypeptide chains
The secondary structure of a protein
The secondary structure of a protein is the shape the polypeptide chain forms as a result of hydrogen bonding
The secondary structure of a protein is the shape the polypeptide chain forms as a result of hydrogen bonding.
This is most often a what?
This is most often a spiral known as the a-helix
The secondary structure of a protein is the shape the polypeptide chain forms as a result of hydrogen bonding.
This is most often a spiral known as the a-helix, although what occur?
This is most often a spiral known as the a-helix, although other configurations occur
The tertiary structure of a protein is due to what?
The tertiary structure of a protein is due to the:
- Bending
- Twisting
of the polypeptide helix
The tertiary structure of a protein is due to the bending and twisting of the polypeptide helix into a what?
The tertiary structure of a protein is due to the:
- Bending
- Twisting
of the polypeptide helix into a compact structure
The tertiary structure of a protein is due to the bending and twisting of the polypeptide helix into a compact structure.
All 3 types of bond, disulphide, ionic and hydrogen, contribute to what?
All 3 types of bond:
- Disulphide
- Ionic
- Hydrogen
,contribute to the maintenance of the tertiary structure
The quaternary structure of a protein arises from what?
The quaternary structure of a protein arises from the combination of:
- A number of different polypeptide chains
- Associated non-protein (prosthetic) groups
The quaternary structure of a protein arises from the combination of a number of different polypeptide chains and associated non-protein (prosthetic) groups into what?
The quaternary structure of a protein arises from the combination of a number of different polypeptide chains and associated non-protein (prosthetic) groups into a:
- Large
- Complex
protein molecule
The quaternary structure of a protein arises from the combination of a number of different polypeptide chains and associated non-protein (prosthetic) groups into a large, complex protein molecule, for example what?
The quaternary structure of a protein arises from the combination of:
- A number of different polypeptide chains
- Associated non-protein (prosthetic) groups
into a large and complex protein molecule, for example haemoglobin
Large proteins often form complex molecules containing a number of individual polypeptide chains that are linked in various ways.
There may also be non-protein (prosthetic) groups associated with the molecules, such as what?
There may also be non-protein (prosthetic) groups associated with the molecules, such as the iron-containing haem group in haemoglobin
The most reliable protein test is the Biuret test, which detects peptide bonds.
The Biuret test is performed as follows:
Place a sample of the solution to be tested in a test tube and add an equal volume of sodium hydroxide solution at room temperature.
Add a few drops of very dilute (0.05%) copper (II) sulfate solution and mix gently.
What indicates the presence of peptide bonds and hence a protein?
A purple coloration indicates the presence of:
- Peptide bonds
- Hence a protein
Fibrous proteins form what?
Fibrous proteins form long chains
Fibrous proteins form long chains that do what?
Fibrous proteins form long chains that run parallel to one another
Where is collagen found?
Collagen is found in tendons
Collagen is found in tendons.
What do tendons do?
Tendons join muscles to bones
Collagen is found in tendons.
Tendons join muscles to bones.
When a muscle contracts, the bone is what?
When a muscle contracts, the bone is pulled in the direction of the contraction
Think of the polypeptide chain as a piece of string. In a fibrous protein, what?
In a fibrous protein, many pieces of the string are twisted together into a rope
Think of the polypeptide chain as a piece of string. In a fibrous protein, many pieces of the string are twisted together into a rope, while in a globular protein, what?
In a:
- Fibrous protein, many pieces of the string are twisted together into a rope
,while
- Globular protein, the pieces of string, usually fewer, are rolled into a ball
