The Science Co.

Unit #1: Chemistry of Life

Water is a Polar Molecule made of 1 Oxygen and 2 Hydrogen. It is comprised of Covalent Bonds within the Oxygen & Hydrogen, and Hydrogen Bonds between the weak charges of the Hydrogen and Oxygen between molecules. The weak hydrogen bonds allow the molecule to obtain its various unique features. These features are adhesion, cohesion, and high specific heat. Adhesion is the ability for water to attract itself. Cohesion is the ability for water to attract to other molecules. Waters high specific heat allows water to absorb a lot of energy before changing temperature, helping to moderate the earths temperature. Hydrophobic molecules push water away, while hydrophilic molecules attract water. Macromolecules are also large building blocks in the cell. These macromolecules are Carbohydrates, Lipids, Nucleic Acids, and Proteins. Carbohydrates require carbon, hydrogen, and oxygen to be produced. Lipids also require carbon, hydrogen, and oxygen, while Nucleic Acids require carbon, hydrogen, oxygen, and nitrogen. Finally, proteins require carbon, hydrogen, oxygen, nitrogen, phosphates, and sulphur. These monomers use dehydration synthesis to form macromolecules, and hydrolysis to break them apart.

Unit #2: Cell Structure and Function

There are many important subparticles in the cell that help regulate the internal and extrenal environments.Ribosomes synthesise proteins to be used by the cell. The endoplasmic reticulum (ER) is split into two parts: The Rough ER carries out protein synthesis and the Smooth ER participates in lipid synthesis. The Golgi Complex packages and sorts proteins. The Mitochondria produce ATP through cellular respiration. Lysosomes help recycle old cell parts, and help the cell undergo controlled death. Vacuoles store and release molecules and waste. Chloroplasts are only in plants, and help produce sugars through photosynthesis. Cell size also plays a key part in cell function, as the cell size increases at a faster rate than surface area. The cell membrane is also selectively permeable, meaning that it only lets in certain molecules. Molecules also make their way into the cell through passive transport, active transport, endocytosis, and exocytosis. Passive transport allows molecules to get into a cell without energy. Active transport transports molecules into a cell with ATP. Endocytosis takes bulk material into the cell, while exocytosis removes bulk material from the cell. Water also moves passively from zones of high water pressure to zones of low water pressure. This allows cells to balance solute concentration inside the cell. These are mentioned through the Hypertonic, Hypotonic, and Isotonic Solutions.

Unit #3: Cellular Energetics

Glucose turns to ATP through glycolysis. Enzymes are proteins that lower the activation energy of a chemical reaction. Proteins denature through abnormal temperatures and PH's. Competitive inhibitors release molecules similar to the target molecule to take up free enzymes. Noncompetitive inhibitors bind to enzymes to change their active sites. Energy is lost through each reaction, called entropy. The electron transport chain is a chain that allows charged molecules to be transported. Light dependent and light independent photosynthesis. Photosystem 1 and 2. Proton gradient. Fermentation and cellular respiration. Krebs cycle. ATP Synthase.

Unit #4: Cell Communication & Cell Cycle

Cell communication: Juxtacrine, Autocrine, Paracrine and Endocrin. The 3 steps of cell signaling are the ligand, transduction, and response. Quorum sensing is cell signaling between bacteria. Mutations in transduction pathway can lead to cancer. Negative feedback loops continue until a condition is met, while positive feedback loops continue while a condition is met. The cell cycle goes through: G1, S, G2 checkpoints. Cellular replication goes through: Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis. Cell plate and cleavage furrow.

Unit #5: Heredity

Diploid cells have 2 chromosomes, while Haploid cells only have 1. Meiosis is meant to ensure variation in a population. Crossing over is when parent chromosomes share DNA. Independent assortment is the idea that genes get sorted into alleles different than them. Mendelian genetics , incomplete dominance, codominance, and polygenic inheritance are all ideas about genetics. Sex linked genes are genes present on sex chromosomes. Punnett squares are a way to visualize mendelian genetics. Chromosomes are eukaryotic organisms way of holding genetic material.

Unit #6: Gene Expression & Regulation

Dna is made with four bases, ATCG. RNA is 4 bases, AUCG. DNA forms a double helix structure. DNA has a sugar phosphate backbone. DNA contains information to create proteins. Only eukaryotes have chromosomes while prokaryotes have circular DNA molecules called plasmids. A -> T/U C -> G. Purines and pyrimidines are forms of nitrogen bases of different shapes. Purines must pair with pyrimidines. DNA runs from 5' to 3'. First Helicase unwraps DNA, breaking hydrogen bonds. Topoisomerase reduces tension to prevent re-coiling. RNA primase sets an area to start DNA polymerase action. DNA polymerase works from 5' - 3'. DNA polymerase works in small segments, called Okazaki Fragments. These fragment are glued together with ligase. Every time DNA is replicated, it degrades, eventually leading to a loss of bodily function. mRNA carries genetic information and is transcribed from DNA. tRNA is a protein that carries amino acids to a polypeptide chain. DNA -> RNA -> Protein. RNA polymerase reads DNA from the promoter and adds complementary nucleotides, forming a primary RNA transcript. In prokaryotes, transcription and translation occur in tandem. Genes are regulated to turn off or on genes. In prokaryotes, operons are groups of genes. Genes are regulated with either repressor or corepressor proteins. These proteins either prevent or allow gene expression. Also known as alterations in the gene sequence. Point, insertion, deletion, and frameshift are all types of mutations that DNA can undergo. The effects can be either positive, negative, or neutral. External factors like radiation can also mutate DNA. Errors in duplication and meiosis also cause mutations. Recombinant DNA is DNA from combining genetic material from different sources. Cloning is perfectly recreating the genetic information of an organism. PCR is a technique used to create many copies of a DNA fragment. Gel Electrophoresis uses varied sized DNA fragments to form a DNA profile. GMO's are organisms with altered genetic material.

Unit #7: Natural Selection

Evolution is change in the gene pool over time. Natural selection is the tendency for a trait to become more or less common in a population. Traits that benefit the individual will become more common because the individuals with a positive trait will be more likely to survive and pass genes on. 4 traits must be present to apply the Hardy Weinburg equation: Large population, variation in the population, no gene flow, no natural selection, and random mating. Bottlenecks occur when the population reduces, resulting in a loss of genetic variation. The founder effect occurs when a small group of individuals break off from the original population, resulting in a low genetic diversity. All species derive from a common ancestor. Speciation is when one species diverges into multiple species. Cladograms can represent the genetic distance between different species.

Unit #8: Ecology

Ecology is the interactions between organisms and the environment. Carrying capacity is the amount of organisms an environment can support. Organisms adapt to respond to environmental stimuli. Organisms also communicate to exchange information. Population size depends on total available energy. If an environment has enough energy to support a larger population, the population will likely grow whilst the opposite is also true. Reproduction without limit is known as exponential growth. When the limit is reached, the population will overshoot it before falling below the limit. Diversity is important as it helps ensure the survival of a species in the event of a catastrophic happening. It can be measured through the Simpson's Diversity Index, which measures the species diversity on a scale from 0 - 1. Keystone species are species that is essential to the survival of an ecosystem. Producers are energy producing organisms, such as plants and algae. Abiotic factors are nonliving factors in an environment. Biotic factors are the living factors in an environment.

Biology