1What is the main aim of protein assembly lectures?
To understand protein synthesis, assembly, and sorting
2What stages are involved in protein assembly?
Protein synthesis, protein modification, and protein sorting
3What is the overall flow from DNA to protein?
DNA → mRNA (transcription) → protein (translation)
4What cellular process directly produces protein?
Translation
5What is translation?
Synthesis of a polypeptide from an mRNA template
6What are the main stages of translation?
Initiation, elongation, termination, and recycling
7What happens during initiation?
Ribosome assembles at the start codon on mRNA
8What happens during elongation?
Amino acids are added stepwise to the growing polypeptide chain
9What happens during termination?
A stop codon triggers release of the polypeptide chain
10What is ribosome recycling?
Separation and reuse of ribosomal subunits after termination
11What is meant by peptide chain assembly?
Stepwise joining of amino acids into a polypeptide
12What type of bond joins amino acids in a peptide chain?
Peptide bond
13What are 3 types of RNA involved in translation?
mRNA, tRNA, and rRNA
14What is the role of mRNA?
Provides codons specifying amino acids
15What is the role of tRNA?
Matches anticodons to codons and carries amino acids
16What is the role of rRNA?
Forms ribosome structure and catalyses peptide bond formation
17What is a codon?
A 3-base mRNA sequence specifying an amino acid or stop signal
18What is an anticodon?
A 3-base tRNA sequence complementary to an mRNA codon
19What are ribosomes composed of?
Two subunits made of rRNA and proteins
20What ribosome sizes are mentioned in the lectures?
70S, 80S, and 60S
21What determines ribosome size?
Species/type of organism
22Where are ribosomes produced?
In the nucleolus
23How do ribosomal subunits leave the nucleus?
Through nuclear pores
24Why is ribosome recycling important?
Increases efficiency of protein production
25What is ribosome regulation?
Control of ribosome production and activity in the cell
26What are the 4 levels of protein structure?
Primary, secondary, tertiary, and quaternary
27What is primary protein structure?
Amino acid sequence
28What is secondary protein structure?
Local folding patterns (alpha helices and beta sheets)
29What is tertiary protein structure?
Overall 3D shape of one polypeptide
30What is quaternary protein structure?
Assembly of multiple polypeptide subunits
31What happens after translation before a protein becomes functional?
Folding/assembly and post-translational modification
32What is meant by the protein journey?
The path a protein takes from DNA to its final location
33What does the intracellular site of translation influence?
The destination of the protein
34What is protein modification?
Chemical/structural changes made to proteins after synthesis
35Why are protein modifications important?
They affect protein activity, stability, and targeting
36Which organelle plays a central role in protein modification and sorting?
The Golgi apparatus
37What did Palade’s experiments demonstrate?
The secretory pathway of proteins
38What pathway was identified by Palade?
Endoplasmic reticulum → Golgi → secretion
39What is the secretory pathway?
The route proteins take through the ER and Golgi for export
40What is protein sorting?
Directing proteins to their correct cellular destination
41What is a signal sequence?
A targeting sequence within a protein
42How long are signal sequences?
Approximately 15–60 amino acids
43What happens to signal sequences after targeting?
They may be removed by signal peptidase
44What is a signal patch?
A targeting signal formed from non-continuous amino acids
45When is a signal patch exposed?
When the protein folds correctly
46What do protein signals control?
Protein transport and localisation
47Where are protein targeting signals encoded?
Within the amino acid sequence of the protein
48Who discovered that proteins contain intrinsic targeting signals?
Günter Blobel
49What recognition did Günter Blobel receive for this discovery?
1999 Nobel Prize in Physiology or Medicine
50What is the key discovery of protein sorting research?
Proteins carry their own destination information
51What is the overall conclusion about protein assembly?
A multistage regulated process involving synthesis, modification, and sorting