Answer:

1) What is the SwissProt code and the accession number of the human lysozyme C protein? MRS query: de:Lysozyme os:human
Thus, 10 entries found (aug 2017). LYSC_HUMAN is the one with Accession Number P61626. Most other hits actually are lysozyme-like things. 2) Which is the enzyme code (EC) of lysozyme?
Which reaction do these enzymes catalyse?
Hint: Also look in the ENZYME database for information.
EC 3.2.1.17, but in that EC database entry there is a warning about the class 3.2.1.14 having similar activity.
3) Find the gene for the human lysozyme.
What is the EMBL code and the accession number?
in SwissProt there are several pointers to EMBL. Most are mRNA (and for most genes multiple mRNA variants can be found in the body), while X14008 is the complete gene. Later you will learn how to look up the gene in dedicated gene-databases. 4) How many introns does the human lysozyme gene contain?
Three 5) Which repetitive elements are present in the gene, and where are they located?
Do they have an effect on the coding region?
The Alu sequences do not influence the coding region. The first 3 Alu seq are present in an intron, the fourth Alu sequence is in the 3' UTR of the mRNA.
6) On which chromosome is the gene located?
Hint: Ensembl is a useful Human Genome Database/browser. The Ensembl annotation tells you it is chromosome 12 at location 69,348,341-69,354,234. In the graphical window of the Ensemble hit you can also find its layout (introns, exons, neighbours in the genome, etcetera; but that does not encompass material for the examination.
7) Are there any hereditary diseases associated which this gene?
For each disease you find give two lysozyme mutations which cause this disease.
Hint: use the (O)MIM database.
Two (O)MIM entries. 105200; phenotype. 153450; gene.
One describes the disease, the other the five (june 2007) amyloidosis causing mutations.
8) Search for related protein patterns of the lysozyme protein sequence. Which protein pattern appears to be characteristic for lysozyme protein family?
HINT: PROSITE is a database with protein patterns
We will later explain what this means, but the pattern is: C-x(3)-C-x(2)-[LMF]-x(3)-[DEN]-[LI]-x(5)-C
(You get links to a profile/matrix and to a pattern file, for now we need the pattern. Profiles will be explained at a later stage). 9) Cysteine bridges
How many disulfide bridges does lysozyme contain?
What are the residue numbers of the bridged cysteines regarding to the SwissProt file?
What are the residue numbers of the bridged cysteines regarding to the PDB file?
Do you understand what causes this difference in residue numbering?

 SSBOND records in PDB:
 6-128
 30-116
 65-81
 77-95