Biology

• Sun formation created a gravitational pull, attracting different rocks and space debris into an orbital.
• The formation of the orbital subsequently formed the Earth through the accumulation of such debris.
• The Earth's conditions, lack of free oxygen and higher concentrations of carbon dioxide and methane, resulted in higher temperatures and ultraviolet light penetration.
• Folding of a protein is described as the conformation of a protein; the precise position of each atom in a globular protein is 0 conformation.
• Did not produce ALL organic molecules required for life
• Collagen is a tube-like protein with high tensile strength, made of primary structure of repeating sequences of Amino Acids (P-G-X), where P stands for proline or hydroxyproline, which prevents the formation of an alpha helix.
• Provides proof of the first conditions required for life (i.e the formation of macromolecules)
• The R group of the X in collagen is inverted, pushing the hydrophobic to the center.
• Proof for spontaneous generation
• Does not account for later steps in the process (i.e the carbon compounds forming life)
• Demonstrated that molecules such as amino acids can be generated spontaneously under certain conditions
• Huge assumption of prebiotic conditions
• The design of the experiment allow it to be replicated by other scientists
• Did not mimic every condition on Earth
• Massive assumption of the prebiotic conditions
• Hot conditions through high amounts of greenhouse gases trapping heat in the atmosphere and comet and asteroid impacts, also generated heat.
• Less ozone leads to more UV light, resulting in hotter conditions.
• More Ultraviolet Radiation produces higher energies.
• Carbon compounds, such as carboxylic acids, aldehydes, amino acids, and bases, that are part of DNA and RNA, are required for the formation of cells.
• Cells are the basic unit of life, all organisms are composed of at least one cell, all cells come from pre-existing cells, and all living organisms have at least one cell.
• Viruses do have genetic material (DNA or RNA), but they do not possess most of the characteristics of living organisms.
• Cells are highly complex structures that can currently only be produced by the division of pre-existing cells.
• Cells are the smallest units of self-sustaining life.
• The Cell Theory states that cells are the basic unit of life, all organisms are composed of at least one cell, and all cells come from pre-existing cells.
• Cells are capable of carrying out metabolism, maintaining homeostasis, responding to external stimuli, reproducing, and maintaining their own genetic material.
• Cells are incapable of spontaneous generation.
• Cells are the basic unit of life, all organisms are composed of at least one cell, and all cells come from pre-existing cells.
• Homogenization involves breaking open cells using a blender, is done in a cold isotonic and buffered solution, and exposes intracellular contents of the cell through breaching of the cell wall/membrane.
• Ultracentrifugation involves spinning a filtered solution at different speeds in a centrifuge, forming pellets of the most dense organelles at the bottom, and removing the supernatant liquid at each speed.
• The Golgi Apparatus is located between the rough endoplasmic reticulum and the plasma membrane, allows the vesicles to exit through exocytosis, and is found between the rER and the plasma membrane.
• Chloroplasts have a thylakoid membrane for absorption of light, electron transport chain, and ATP synthesis, grana which increase surface area, a small thylakoid space inside the grana for the rapid accumulation of protons, a stroma containing DNA, ribosomes and all of the enzymes required for the light-independent reactions, the Calvin cycle, of photosynthesis, and a double membrane with a pore, as in nuclear membranes.
• Prokaryotes do not have a nucleus, which means there is no separation of the processes of transcription and translation.
• Mitochondria have an outer membrane with channels for pyruvate to enter the mitochondrion, an intermembrane space, an inner membrane containing the proteins of the electron transport chain and ATP synthase, cristae, and a matrix containing DNA, ribosomes and all of the enzymes involved in the link reaction and the Krebs cycle.
• The separation of the nucleus and cytoplasm into separate compartments limits the separation of the activities of gene transcription and translation, protects DNA from potentially harmful reactions in the cytoplasm, and allows transcription of DNA to mRNA to occur in the nucleus.
• Ultracentrifugation is used to isolate different organelles so they can be studied, involves breaking open cells to release the contents and separating organelles, and requires cells to be prepared in a cold isotonic and buffered solution.
• Ribosomes synthesize polypeptides (proteins) by translating mRNA, are composed of a large ribosomal subunit and a small ribosomal subunit, both composed of proteins and ribosomal RNA (rRNA), and have a binding site for mRNA.
• The plasma membrane is a phospholipid bilayer which surrounds and encloses the cell, controls what enters and exits the cells, and is not normally considered an organelle by scientists.
• Prokaryotic cells have fewer organelles than eukaryotic cells due to their smaller cells and concentration on a more limited range of functions.
• Some proteins contain amino acids that are not in the basic repertoire of 20.
• In most cases this is due to one of the 20 being modified after a polypeptide has been synthesized.