AQA A LEVEL BIOLOGY PAPER 1 COMPLETE
STUDY GUIDE WITH SOLVED QUESTIONS
◉ what is meant by 'secondary sequence' of a protein.
Answer: The way in which the primary structure of a polypeptide
chain folds e.g. alpha helix or beta pleated sheets. shape is held by H
bonds.
◉ what is meant by 'tertiary sequence' of a protein.
Answer: This is the overall 3-D structure of the protein.
The shape of the protein is held together by H bonds and ionic bonds
and disulfide bridges.
◉ what is meant by 'quaternary sequence' of a protein.
Answer: If a protein is made up of several polypeptide chains that
are linked in various ways, the way they are arranged is called the
quaternary structure.
◉ Biuret is made up of....
Answer: equal volumes and copper sulphate and sodium hydroxide
◉ what are fiberous proteins made up of?.
,Answer: made of long molecules arranged to form fibres (e.g. in
keratin). Several helices may be wound around each other to form
very strong fibres.
◉ what are globular proteins made up of?.
Answer: made of chains folded into a compact structure. One of the
most important classes are the enzymes. Although these folds are
less regular than in a helix, they are highly specific and a particular
protein will always be folded in the same way.
◉ what kind of protein is collagen?.
Answer: fibrous
◉ what kind of protein is haemoglobin?.
Answer: globular
◉ what is haemoglobin made up of?.
Answer: two α polypeptide chains
two β polypeptide chains
an inorganic prosthetic haem group (Fe2+)
◉ Describe the structure of collagen..
, Answer: three polypeptide chains wound around each other.
Hydrogen bonds form between these chains. Coils forms Covalent
Cross Links with each other. Covalent cross links are staggered.
◉ what are the functions of collagen?.
Answer: 1. Form the structure of bones
2. Makes up cartilage and connective tissue
3. Prevents blood that is being pumped at high pressure from
bursting the walls of arteries
4. Is the main component of tendons, which connect skeletal muscles
to bones
◉ what type of bond forms between the phosphate group and
deoxyribose sugar in DNA?.
Answer: phosphodiester bond
◉ why is DNA stable?.
Answer: 1. the phosphodiester backbone protects the more
chemically reactive organic bases inside the double helix
2. many hydrogen bonds link the base pairs together, so it adds
strength overall.
◉ how is DNA adapted to carrying out its function?.
STUDY GUIDE WITH SOLVED QUESTIONS
◉ what is meant by 'secondary sequence' of a protein.
Answer: The way in which the primary structure of a polypeptide
chain folds e.g. alpha helix or beta pleated sheets. shape is held by H
bonds.
◉ what is meant by 'tertiary sequence' of a protein.
Answer: This is the overall 3-D structure of the protein.
The shape of the protein is held together by H bonds and ionic bonds
and disulfide bridges.
◉ what is meant by 'quaternary sequence' of a protein.
Answer: If a protein is made up of several polypeptide chains that
are linked in various ways, the way they are arranged is called the
quaternary structure.
◉ Biuret is made up of....
Answer: equal volumes and copper sulphate and sodium hydroxide
◉ what are fiberous proteins made up of?.
,Answer: made of long molecules arranged to form fibres (e.g. in
keratin). Several helices may be wound around each other to form
very strong fibres.
◉ what are globular proteins made up of?.
Answer: made of chains folded into a compact structure. One of the
most important classes are the enzymes. Although these folds are
less regular than in a helix, they are highly specific and a particular
protein will always be folded in the same way.
◉ what kind of protein is collagen?.
Answer: fibrous
◉ what kind of protein is haemoglobin?.
Answer: globular
◉ what is haemoglobin made up of?.
Answer: two α polypeptide chains
two β polypeptide chains
an inorganic prosthetic haem group (Fe2+)
◉ Describe the structure of collagen..
, Answer: three polypeptide chains wound around each other.
Hydrogen bonds form between these chains. Coils forms Covalent
Cross Links with each other. Covalent cross links are staggered.
◉ what are the functions of collagen?.
Answer: 1. Form the structure of bones
2. Makes up cartilage and connective tissue
3. Prevents blood that is being pumped at high pressure from
bursting the walls of arteries
4. Is the main component of tendons, which connect skeletal muscles
to bones
◉ what type of bond forms between the phosphate group and
deoxyribose sugar in DNA?.
Answer: phosphodiester bond
◉ why is DNA stable?.
Answer: 1. the phosphodiester backbone protects the more
chemically reactive organic bases inside the double helix
2. many hydrogen bonds link the base pairs together, so it adds
strength overall.
◉ how is DNA adapted to carrying out its function?.
