Maahi's Biology Connections

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Genetics

Chromosomes

DNA coils around histones (proteins) forming nucleosomes which supercoil into chromosomes

Meiosis

Genetic Modification

Insulin (hormone that controls blood sugar levels) can be obtained from the plasmid of E.coli

Genes

Most genes encode proteins but some don't (tRNA)

Cell Biology

Cell Theory

Cell Division: cells are only formed through the division of other cells

Prokaryotes

One chromosome consisting of a circular DNA molecule made of naked DNA

May have additional plasmids to contain genes, often related to specific function

Eukaryotes

Multiple linear DNA molecules packaged with histone proteins (globular and wider than DNA forming nucleosomes)

Organelles

Centrioles: release spindle fibers that pull chromosomes apart

Cell Membrane

made up of phospholipids (hydrophilic heads and hydrophobic tails)

cholesterol reduces membrane fluidity and permeability

Membrane Transport

Exocytosis and Endocytosis

Help regulate the cell shape change during cell division due to CDK

Cytoplasm

Contains enzymes to catalyze the reactions that take place

Ultrastructure of Cells

Ribosomes: synthesize proteins and translate mRNA

Molecular Biology

Carbohydrates

Structural support to plant cells and fungi (cell wall)

Hydrogen Bonds

Connects nucleotides in DNA (CG/TA)

Protein Folding: stabilizes the 2°, 3° and 4° structure in proteins

Proteins

Enzymes are proteins

Responsible for most of the human body functions

Regulation in body

Homeostasis: self-regulating process cells conduct to maintain stability while adjusting to changing external conditions

Metabolism: anabolism and catabolism

Lipids

phospholipids: glycerol + 2 fatty acids + 1 phosphate group

Steroids

Cholesterol

Nucleic Acids

Base Pairing

Two nitrogenous bases bound to each other by hydrogen bonds

Adenine = Thymine (DNA)/Uracil (RNA)

Cytosine ≡ Guanine

Translation

Polypeptide chain released from Exit site is inactive so it begins folding

Transcription

Synthesis of an RNA sequence from DNA template

occurs in the nucleus

Mitosis

Cyclins control the progression of the cell cycle by binding to Cyclin Dependent Kinases (CDKs)

Maahi's Biology Connections