General Chemistry

• Prokaryotes are from the Greek words' "pro", which means "before", and "karyon" which means nut or kernel" are cells without a true nucleus.
• Eukaryotes are from the Greek word "eu", meaning true, and "karyon", meaning "nut or kernel" are cells with a true nucleus, which are bound by the nuclear membrane.
• Prokaryotes are unicellular. They are made up of only one cell and are microscopic.
• Eukaryotes are multicellular. They are made up of many cells and are macroscopic.
• Prokaryotes - bacteria and protozoa
• Eukaryotes - plants and animals
• Cell Wall - All prokaryotes have a cell wall that adds structural support, and acts as a barrier against outside forces
• Flagella - Primarily used for cell movement. The prokaryotic flagellum spins, creating a foward movement by a corkscrew shaped filament.
• Capsule - Protects the cell when it is engulfed by other organisms. Assists in retaining moisture, and helps the cell adhere to surfaces and nutrients.
• Pili - Are hair-like structures on the surface of the cell that attach to other bacterial cells or surfaces.
• Nucleoid - Where the single circular piece of chromosomal DNA is stored.
• Plasmid - Some prokaryotes also carry smaller circles of DNA called plasmids. They are physically separate from, and can replicate independently of the chromosomal DNA.
• The genetic information on the plasmids is transferable between cells, allowing prokaryotes to share abilities, such as antibiotic resistance.
• Prokaryotes are the smallest type of cells, averaging 2-5µm or micrometers in diameter.
• Cell division happens through binary fission, a type of asexual reproduction that produces two identical cells.
• Cell membrane - composed of a phospholipid bilayer embedded with proteins and carbohydrates. They are semipermeable.
• Cytoplasm - enclosed within the cell membrane. The organelles can move within and around the cytoplasm.
• Cytosol - semifluid substances where the different organelles are suspended.
• Cytoskeleton - helps cytoplasm have its structure. It helps cells maintain their shape and internal organization.
• Centrioles - helps in the separation and transfer of genetic materials in the cells called chromosomes.
• Centrioles - are only visible in actively dividing cells.
• Nucleus (plural: Nuclei) - where most genetic processes take place.
• Nuclear Envelope - boundary of the nucleus.
• Nucleoplasm - inside the nuclear envelope
• Chromatin - combination of DNA and proteins
• Ribosome - work with the other parts of the cell to synthesize proteins
• Protein synthesis starts inside the nucleus
• Endoplasmic Reticulum (plural: endoplasmic reticula) - membrane-bound organelle that forms a network of interconnected sacs called cisterna (plural: cisternae)
• Lumen - in between endoplasmic reticulum's membranes
• Rough Endoplasmic Reticulum produces proteins.
• Smooth Endoplasmic Reticulum produces lipids.
• In the pancreas and digestive tract, proteins in the form of enzymes break down food.
• Phospholipids make up the bilipid layer of the cell membrane.
• Cholesterol regulates the cell membrane's fluidity.
• Cis Face - facing the Endoplasmic Reticulum
• Trans Face - facing the cytoplasm
• Hydrolytic Enzyme - proteins that use water to break downsubstances that serve several functions:

  1. Digest food
  2. Recycle old components of the cell
  3. Kill invading microorganisms
• Mitochondrion (plural: Mitochondria)

  • Outer Membrane - outer covering
  • Inner membrane - folded many times to form cristae
  • Ribosome and DNA
• Cell Wall - distinguishes plant cells from animal cells
• Celulose - a polysaccharide which is a substance composed of a long chain of carbohydrates