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what makes proteins in a cell

Inside a cell, ribosomes make proteins by following instructions encoded in DNA and copied into RNA.

The one-sentence version

Proteins in a cell are made by ribosomes, which read messenger RNA (mRNA) copied from DNA and link amino acids together into a protein chain.

The “Quick Scoop” on what makes proteins in a cell

Think of a cell as a tiny factory.
Proteins are its products, and several “departments” cooperate to build them.

1. The blueprint: DNA in the nucleus

  • DNA lives in the nucleus in eukaryotic cells (like human cells).
  • A gene (a section of DNA) holds the coded recipe for a specific protein.
  • During transcription , enzymes called RNA polymerases copy that gene into a messenger RNA (mRNA) molecule.

You can imagine the nucleus as the main office, where the original recipe book (DNA) is kept safe, and mRNA is a photocopy of just one recipe.

2. The messenger: mRNA

  • The newly made mRNA carries the protein recipe out of the nucleus into the cytoplasm.
  • Its sequence is written in “words” of three bases called codons , each coding for one amino acid.

3. The builders: ribosomes

  • Ribosomes are the actual machines that make proteins.
  • They can float freely in the cytoplasm or attach to the rough endoplasmic reticulum (RER).
  • Ribosomes “read” the mRNA codons and catalyze the linking of amino acids into a growing chain (a polypeptide).

4. The delivery trucks: tRNA and amino acids

  • Transfer RNA (tRNA) molecules act like small adaptors with two ends:
    • One end recognizes a specific mRNA codon.
    • The other end carries the matching amino acid.
  • As the ribosome moves along the mRNA, tRNAs keep bringing in the correct amino acids, which the ribosome joins together with peptide bonds.

Picture a conveyor belt (mRNA) passing through a machine (ribosome) while small carts (tRNAs) bring in parts (amino acids) in the right order.

5. The full process: protein synthesis

Biologists often summarize this with the “central dogma”:

  • DNA → RNA → Protein.

In slightly more detail:

  1. Transcription: DNA in the nucleus is copied into mRNA.
  1. mRNA processing (in eukaryotes): mRNA is edited and prepared, then exits the nucleus.
  1. Translation: Ribosomes in the cytoplasm (or on RER) read mRNA and build the amino acid chain with help from tRNA.
  1. Folding and modification: The chain folds into a specific 3D shape and may be chemically modified to become a fully functional protein.

Where in the cell does this happen?

  • Nucleus : DNA stored; transcription (making mRNA) happens here in eukaryotes.
  • Cytoplasm : Translation (actual protein building) happens here on ribosomes.
  • Rough ER : Ribosomes attached here make many proteins that will be secreted or sent to cell membranes.

Mini FAQ

So, what exactly “makes” proteins?

  • The machinery that makes proteins is primarily the ribosome , using mRNA instructions, tRNA helpers, and amino acids as raw material.

Does a cell need proteins to make proteins?

  • Yes: the process itself uses many enzymes and protein factors, but they ultimately come from earlier, simpler versions and from evolutionary history, not from a “paradox” loop.

Information gathered from public forums or data available on the internet and portrayed here.