Sunday, 24 July 2016


Ribosomes are the non-membranous organelles present all over the living kingdom except viruses. They are  present both in prokaryotic and eukaryotic cells though with different configurations. They are the chief protein factories in the cells. 70 S ribosomes are present in prokaryotic cells and their host cells - mitochondria and plastids (chloroplasts). Eukaryotic cells consist of 80S ribosomes either fitted on rough endoplasmic reticulum or freely suspended in cytoplasm. Ribosomes consist of structural RNA called ribosomal RNA. Besides this ribosomes need messenger RNA and transport RNA to carry out the process of protein synthesis.

1) Where does biological protein synthesis take place?
A) Ribosomes
2) What are the protein factories?
A) Ribosomes
3) What are the work benches for protein synthesis in an eukaryotic cell?
A) Rough Endoplasmic Reticulum
4) How many subunits do make a ribosome?
A) 2
5) Which is the mRNA reader?
A) Smaller Ribosomal Subunit
6) Which part of the ribosome prints proteins as per mRNA?
A) Larger Ribosomal Subunit
7) Which is the translational apparatus in the cell?
A) Ribosome
8) What is the chemical nature of a ribosome?
A) Ribonucleoprotein
9) Which is the ribozyme with peptidyl transferase?
10) What kind of organisms do have only 70S ribosomes?
A) ProkaryoticOrganisms
11) What kind of organelles in eukaryotic cells have 70S ribosomes?
A) Mitochondria & Plastids (Chloroplasts)
12) Who discovered ribosomes through electron microscopic studies?
A) George Emil Palade
13) Who has coined the term "ribosome"?
A) Richard B Roberts
14) What percentage of a ribosome is an rRNA?
A) 65%
15) What is meant by 'S' in 70S ribosomes?
A) Svedberg Unit
16) Which unit is used to denote the rate of sedimentation coefficients of cellular organelles in centrifugation experiments?
A) Svedberg Unit
17) What are the two subunits of a 70S ribosomes?
A) 50S & 30S
18) What are the two subunits of a 80S ribosome?
A) 60S & 40S
19) What is the most suitable method to study ribosomal structure?
A) X-ray crystallography
20) What is a unit of 3 nucleotides?
A) Codon
21) Where is anti-codon located?
A) Aminoacyl-tRNA on smaller units
22) What is the seat of peptidyl-tRNA?
A) Larger Ribosomal Subunit
23) What is the start codon?
24) Where are free ribosomes located?
A) Cytosol
25) Where are membrane bound ribosomes present?
A)Rough Endoplasmic Reticulum
26) Where are ribosomes produced in an eukaryotic cell?
A) Nucleolus & Cytoplasm
27) Name the glycoprotein that binds ribosomes to endoplasmic reticulum.
A) Ribophorin
28) What is the core of a ribosome?
29) What are paladesomes?
A) Ribosomes
30) How do you describe an mRNA with a number of ribosomes on it?
A) Polysome or polyribosome
31) What are the building blocks of proteins?
A) Amino acids
32) What are the carriers of amino acids?
A) tRNAs
33) What are the carriers of DNA information?
34) How does endoplasmic reticulum get rough nature?
A) Due to ribosomes
35) What is the chief function of RER?
A) Protein Synthesis
36) Who did first notice ribosomes?
A) Albert Claude
37) How did Claude call ribosomes?
A) Microsomes
38) Who has coined the word "ribosomes"?
A) RB Roberts
39) Where are membrane bound ribosomes present?
A) on Rough Endoplasmic Reticulum
40) How are polysomes along with endoplasmic reticulum described?
A) Ergastoplasm
41) How are ribosomes in mitochondria and chloroplasts are described as per their location?
A) Organelles within organelles

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