Chapter 3 Flashcards
What are the seven characteristics of life?
Life that:
- displays order
- harnesses and utilizes energy
- reproduces
- responds to stimuli
- exhibits homeostasis
- grows and develops
- evolves
Define symbiosis
An inter specific interaction in which the ecological relations between two or more species are intimately tied together
Alternate hypothesis
An explanation of an observed phenomenon that is different from the explanation being tested
Oxidation
The removal of electrons from a substance
Eg) iron rust
Endomembrane system
In eukaryotes a collection of interrelated internal membranous sacs that divide a cell into functional and structural compartments
Transfer RNA
The RNA that brings amino acids to the ribosome for addition to the polypeptide chain
Purine
A type of nitrogenous base with two carbon - nitrogen rings
Endosymbiosis
A symbiotic association in which one symbionts or partner lives inside the other
Protobiont
The term given to a group of abiotically produced organic molecules that are surrounded by a membrane or membrane like structure
Primidine
A type of nitrogenous base with one carbon ring - nitrogen ring
Stromatolites
Fossilized remains of ancient cynobacterial mats that carried out photosynthesis by the water splitting reaction
Heterotrophs
An organism that acquires energy and nutrients by eating other organisms or their remains
Ribozymes
An RNA based catalyst that is a part of the biochemical machinery of all cells
Monomers
Identical or nearly identical subunits that link together to form polymers during polymerization
Polymers
Substances whose molecules have high molar masses and are composed of a large number of repeating units
Among naturally occurs polymers there are proteins, starches, cellulose and latex
Genome
The entire collection of DNA sequence for a given organism
Macromolecules
A very large molecule assembled by the covalent linkage of smaller subunit molecules
Radio metric dating
A dating method that uses measurements of certain radioactive isotopes to calculate the absolute age in years of rocks and minerals
Translation
The use of information encoded in RNA to assemble amino acids into a polypeptide
Selectively permeable
Membranes that selectively allow, impede or block the passage of atoms and molecules
Transcription
The mechanism by which the information encoded in DNA is made into a complementary DNA copy
Autotrophs
An organism that produces its own food source using CO2 and other simple inorganic compounds from its environment and energy from the sun or from oxidation of inorganic substances
3 domains of life
Bacteria, Archaea, eukarya
What is the importance of ribosomes?
They are responsible for protein synthesis. Free ribosomes produce essential proteins for internal cellular activity
Why is DNA better than RNA for storing genetic information?
DNA is a stable storage for genetic information. DNA is 100x more stable than RNA.
- the material must be stable to avoid degradation of the genes when passing them on to the next generation
3 key attributes of the modern cell:
1) a membrane defined compartment- the cell
2) a system to store genetic information and use it to guide the synthesis of specific proteins
3) energy transforming pathways to bring in energy from the surroundings and harness it to sustain life
Liposomes
A lipid vesicle in which the lipid molecules form a bilayer very similar to a cell membrane
