Chapter 1: the foundations of Biochemistry
What are the distinguishing features of living organisms?
1) A high degree of chemical complexity and microscopic organization
2) Systems for extracting, transforming, and using energy from the environment
3) Mechanisms for sensing and responding to alterations in their surroundings
4) A capacity for precise self-replication and self-assembly
5) A capacity to change over time by gradual evolution
defines the periphery of the cell, composed of a lipid bilayer
small organic molecules in the cytosol
Name some components of the cytoplasm
cytosol, metabolites, intermediates of biosynthetic and biodegrative pathways, ions, RNA, coenzymes, etc.
degrade proteins no longer needed by the cell
complete set of genes
smallest microorganism known today
What are the three domains of life?
Eukarya, Archaea, Bacteria
anaerobes that die in the presence of oxygen
anaerobes that can live with or without oxygen
What do aerobes transfer electrons to to form energy?
What do anaerobes transfer electrons to in order to form energy?
nitrate (forms N2), sulfate (forms H2S), or CO2 (forms CH4)
obtain energy from sunlight
derive their energy from oxidation of a chemical fuel
oxidize inorganic fuels (HS- to S, S to SO4-, NO2- to NO3-, Fe2+ to Fe3+)
oxidize organic compounds
obtain all needed carbon from CO2
must obtain carbon from organic nutrients
rigid polymer that gives bacteria their rigidity
rigid polymer that gives archaea their rigidity
provide points of adhesion to the surface of other cells
propels cell through its environment
consists of plasma membrane, peptidoglycan layer, and capsule
small circular piece of DNA in the cytosol
the sample is centrifuged at a low speed to collect larger cells/cell components and the speed continues to increase each time to get a pellet of a different material
the solvent is in different densities (usually with sucrose) and as the sample is centrifuged particles line up at their specific density where each layer can be collected
small molecules whose roles play specifically to plant life (only found in plants-these include scent producing molecules and things such as nicotine, morphine, and caffeine
What weight does a molecule need to be to be considered a macromolecule?
What is the largest component of a cell next to water?
the sum of all the proteins working in a cell
What are the three major functions of polysaccharides?
1)energy rich fuel stores
2)rigid structural components of cell walls
3)extracellular recognition elements that bind to proteins on other cells
shorter polymers of sugars
What is the main function of oligosaccharides
attach to proteins or lipids on the cell's surface and act as specific cellular signals
What are the functions of lipids?
1) structural components of membranes
2) energy rich fuel stores
4) intracellular signals
What are the informational macromolecules
proteins and nucleic acids (named for their large subunit sequences)+ some oligosaccharides
molecules with the same chemical bonds, but different configuration (arrangement)
cell functions only work with certain steroisomers- not all of them