Organelles of a Cell

Nucleus
The nucleus is an organelle enclosed by the nuclear membrane (double membrane), found in eukaryotic cells. The nuclear membrane consists of two layers of lipids / fats - that separate it from the cytoplasm. It controls and regulates the activities of the cell. It contains threads of chromatin (a combination of DNA / Deoxyribonucleic Acid molecules and proteins). In mitosis / when a cell divides, the chromatin undergo condensation (when chromatin cells are compacted when they are organized to fit into a smaller space) - forming chromosomes, which are more tightly coiled.

Nucleolus
The nucleolus is located inside of the nucleus. It is not enclosed by any membrane. The nucleolus contains RNA / Ribonucleic Acid. The RNA is typically a single stranded molecule (while DNA is typically double stranded). The RNA carries genetic information / instructions from DNA (which controls growth, development, and reproduction) and delivers them to proteins. The nucleolus is also responsible for creating and assisting ribosomes, by delivering proteins.

Ribosomes
The ribosomes are essentially a combination of RNA and proteins, thus they are created by the nucleolus. They are not enclosed by any membrane. They decode the messenger RNA / mRNA sequence (unzipped part of DNA) into a string of amino acids (the building blocks of proteins - that are able to form them by linking together in polypeptide chains). The ribosomes could be found floating in the cytoplasm, or they can be attached to the rough ER / endoplasmic reticulum.

Mitochondria
The mitochondria is an organelle enclosed by a double membrane, found in eukaryotic cells. The mitochondria has their unique DNA, different from the nucleus. The mitochondria generates ATP / adenosine triphosphate - a currency of energy for the cell, in the process of cellular respiration. Cellular respiration is a metabolic pathway which breaks down food molecules like glucose and oxygen to create energy.

Stage 1: Glycolysis

  • 1 glucose molecule (six-carbon sugar) → 2 molecules of pyruvate (three-carbon organic matter)
  • NAD+ (oxidized form ; accepts / carries electrons that break down glucose) → NADH (reduced form ; gives electrons that break down glucose) Some energy captured during this process

    • WIP UNFINISHED THERES PROBABLY MANY ERRORS IM REVISING LATER LOL