Biochemistry. Lec

• Biochemistry is the science concerned with the chemical basis of life
• Biochemical processes in life include pathways, biosynthesis, and metabolism to sustain life
• Eukaryotic cells have a true nucleus and are seen in both unicellular and multicellular microorganisms
• Eukaryotic cells have membrane-bound organelles
• Prokaryotic cells have a nucleoid, no true nucleus, and no membrane-bound organelles
• Prokaryotic cells are seen in unicellular microorganisms
• Eubacteria is the largest and oldest domain, and it is prokaryotic in nature
• Archaea is prokaryotic in nature and inhabits extreme environments such as thermophiles, halophiles, barophiles, cryophiles, and methanophiles
• Eukarya is eukaryotic in nature and includes Kingdom Fungi, Kingdom Plantae, Kingdom Animalia, and Kingdom Protista
• A cell is the basic unit of life
• Main parts of a cell include the cell membrane, cytosol, and nucleus (genetic material)
• The cell membrane acts as a gate/barrier, regulates the flow of materials in and out of the cell, and follows the Fluid Mosaic Model
• Components of the cell membrane include the phospholipid bilayer, cholesterol, receptors, and lipid rafts
• The phospholipid bilayer has two layers: hydrophilic head (outside) and hydrophobic tail (inside)
• Cholesterol modulates the fluidity of the membrane and joins the phospholipid bilayer under hot temperatures and separates it under cold temperatures
• Receptors on the cell membrane are for signaling and can be integral or peripheral
• Lipid rafts are involved in signaling and movement, carrying receptors to the next raft
• The cell membrane's semi-permeability allows it to manage what goes in and out of the cell
• Active transport moves against the concentration gradient and may or may not require energy
• Passive transport moves along the concentration gradient and does not require energy
• Simple diffusion does not involve carriers or channels and includes gases like oxygen, carbon monoxide, and cyanide
• Facilitated diffusion requires carriers or channels, such as aquaporins for water and Glucose Transporters for glucose
• Primary active transport requires energy and creates a concentration gradient
• Secondary active transport utilizes the concentration gradient created by primary active transport
• Mitochondria are known as the "Powerhouse of the Cell" and produce ATP through cellular respiration
• Mitochondria have MTDNA found in the mitochondrial membrane and resemble a cell based on the endosymbiotic theory
• Endoplasmic reticulum is infoldings of the nuclear membrane for replication and transcription
• Rough endoplasmic reticulum contains ribosomes and is where protein synthesis occurs
• Smooth endoplasmic reticulum is for lipid synthesis
• Ribosomes are the protein factories composed of proteins and DNA (ribosomal DNA) with subunits varying in size between prokaryotic and eukaryotic cells
• Golgi apparatus packs, receives, and sends proteins, acting as a "Sorting center"
• Lysosomes are known as "Suicide sacs" that recycle unfunctional materials using hydrolytic enzymes
• Chloroplasts contain chlorophyll for photosynthesis and are only found in plant cells
• Cytoskeleton acts as a "Scaffolding" to maintain the shape of the cell and is used by ribosomes as a channel to transport materials around the cell
• Cell division is the process where a parent cell divides to form two daughter cells, serving as a means of reproduction for both prokaryotic and eukaryotic cells
• Mitosis is cell multiplication for somatic cells, producing diploid (2n) cells that are identical to the parent cell
• Meiosis is cell division for gamete cells, producing haploid (n) cells that are non-identical due to DNA recombination
• Interphase is the largest part of the cell division process, consisting of non-dividing cells in a metabolic phase with stages like G1, S, and G2
• Prophase involves the condensation of chromosomes and nuclear envelope breakdown
• Metaphase sees chromosomes align at the cell equator known as the Metaphase Plate