🐱Old Papers Flashcards
Includes 'paper 6'
Outline how changing one amino acid in the β-globin polypeptide of haemoglobin may change the structure and function of a molecule of haemoglobin.
A different amino acid will have a different R-group, which may prevent the formation of bonds between R-groups or may form different bonds between R-groups. This can change the folding of the β-globin polypeptide, altering haemoglobin’s globular shape.
If the new group is non-polar instead of polar, its ability to bind with O2 and CO2 will change.
Explain how molecules of cellulose are arranged into a microfibril.
Cellulose molecules are linear (unbranched) chains arranged in parallel. There are H bonds between the cellulose molecules, specifically between the -OH groups.
Explain why channel proteins are needed for the movement of ions into and out of cells.
Ions are hydrophilic, meaning they cannot pass through the hydrophobic core of the phospholipid bilayer. Channel proteins allow facilitated diffusion to occur, providing a hydrophilic, water-filled pathway, allowing ions to move into and out of the cell.
What are the elements of collagen?
CHON
What are the elements of DNA?
CHONP
What are the monomers of collagen?
amino acids
What are the monomers of DNA?
nucleotides
Name the bond between the DNA monomers.
phosphodiester
Name the bond between collagen monomers.
peptide
Where is the site of production of DNA in eukaryotic cells?
nucleus
Where is the site of production of collagen in eukaryotic cells?
ribosomes
State how the structure of a nucleus is suited to its function of containing DNA.
The nucleus has a double membrane, known as the nuclear envelope, which contains nuclear pores that are too small for DNA to pass through. This helps protect DNA from being broken down by enzymes. The nuclear envelope also separates the nucleus from the rest of the cell, creating a barrier between the nucleus and the cytoplasm.
