Ribosomes: The Engine of the Cell
By Preet, Ravi, Ahaan
Introduction to cell
What is Ribosome?
Types of Ribosomes
Ribosome Structure
Table of contents
01
02
03
04
Ribosome biogenesis
Ribosome Function
Regulation of Ribosomes
Application and Importance
Table of contents
05
06
07
08
Introduction to Cell Structure
01
Cell:
Basic structural and functional unit of life.
Diverse in shape and size, performing specific functions.
Components:
Cell Membrane: Outer boundary, controls substance passage.
Cytoplasm: Gel-like substance holding organelles.
Nucleus: Control center housing genetic material.
Organelles:
Specialized structures performing distinct functions.
Examples: mitochondria, endoplasmic reticulum, ribosomes.
Function:
Cells carry out vital activities essential for life.
Varied roles based on the cell type and organism.
Introduction to Cell
Question 1
Which is the outer boundary and controls the passage of substance passage
Cell wall
Cytoplasm
Cell membrane
None of the above
A
B
C
D
Question 1
Which is the outer boundary and controls the passage of substance passage
Cell wall
Cytoplasm
Cell membrane
None of the above
A
B
C
D
What are Ribosomes?
02
Definition:
Molecular complexes responsible for protein synthesis in cells.
Composed of RNA and proteins.
Location:
Found in the cytoplasm and on the endoplasmic reticulum.
Free-floating or bound to membranes.
Function:
Translate genetic information from mRNA into proteins.
Facilitate the assembly of amino acids into polypeptide chains.
Structure:
Consist of small and large subunits.
Contains ribosomal RNA (rRNA) and proteins.
Importance:
Essential for cell growth, repair, and maintenance.
Fundamental in all living cells for protein production.
What are Ribosomes?
Question 2
Where are Ribosomes found?
Cytoplasm
A
E.R.
B
Both A and B
C
Types of Ribosomes
03
Free Ribosomes:
Location: Floating in the cytoplasm.
Function: Synthesize proteins for internal cellular use.
Examples: Produce enzymes and structural proteins.
Bound Ribosomes:
Location: Attached to the endoplasmic reticulum (ER).
Function: Synthesize proteins for export or insertion into membranes.
Examples: Production of proteins for secretion or membrane-bound proteins.
Similarities:
Both types are involved in protein synthesis.
Composed of small and large subunits, containing ribosomal RNA (rRNA) and proteins.
Types of Ribosomes
Question 3
Bound Ribosomes are attached to E.R
True
False
Ribosome Biogenesis
04
Nucleolus:
Site within the nucleus where ribosomal RNA (rRNA) synthesis begins.
rRNA transcribed from DNA and processed in the nucleolus.
Assembly Steps:
Transcription of rRNA genes.
Processing and modification of rRNA.
Assembly of small and large ribosomal subunits.
Export of mature ribosomal subunits to the cytoplasm.
Factors Involved:
Proteins, enzymes, and specific RNA molecules aid in assembly.
Quality control mechanisms ensure proper assembly
Ribosome biogenesis
Question 4
Where does Ribosome biogenesis take place?
Cell wall
Cytoplasm
Cell membrane
Nucleolus
A
B
C
D
Ribosome structure
05
Composition:
Consists of two subunits: small and large.
Small subunit: Contains a single RNA molecule and proteins.
Large subunit: Composed of rRNA and proteins.
Binding Sites:
A (aminoacyl) site: Binds incoming aminoacyl-tRNA.
P (peptidyl) site: Holds the tRNA carrying the growing polypeptide chain.
E (exit) site: Releases the empty tRNA.
tRNA Interaction:
Ribosomes facilitate the interaction between mRNA and tRNA.
tRNA molecules bring specific amino acids to the ribosome for protein synthesis.
Ribosome structure
Ribosome Function
06
Protein Synthesis:
Translates genetic information from mRNA into proteins.
Process occurs in three main stages: initiation, elongation, termination.
mRNA Interaction:
Ribosomes bind to mRNA and decode the genetic information.
Reading the mRNA codons, ribosomes facilitate the attachment of amino acids.
tRNA Involvement:
tRNA molecules carry amino acids to the ribosome.
tRNA anticodons pair with mRNA codons, specifying the sequence of amino acids in
the polypeptide chain.
Ribosome Function
— George E. Palade
“For a scientist, it is a unique experience to live through a period in which his
field of endeavour comes to bloom – to be witness to those rare moments when the
dawn of understanding finally descends upon what appeared to be confusion only a
while ago – to listen to the sound of darkness crumbling.”
Thank you!
