Ch 1 Flashcards
All proteins in a cell are made by the same 20 different ______?
amino acids
what is the observable characteristic that best distinguishes archaea from bacteria.
archaea is found in harsh environments
The __________ is made up of two concentric membranes and is continuous with the membrane of the endoplasmic reticulum.
nuclear membrane/envelope
where are chlorophyll molecules located in chloroplast
thylakoid membrane
role of the lysosome?
clean up, recycling, and disposal of macromolecules
disposes of unwanted molecules/digestion
Peroxisomes
small, membrane-bound organelles that provide a safe place within the cell to carry out biochemical reactions that generate and remove harmful, highly reactive oxygen species like superoxide and hydrogen peroxide.
Microtubules __________ (do this) and are required to pull duplicated chromosomes to opposite poles of dividing cells.
rapidly reorganize
how much bigger are eukaryotic cells than prokaryotic
10x longer, 1000x more volume
T/F The Golgi apparatus is made up of a series of membrane-enclosed compartments through which materials destined for secretion must pass.
True
Cells can create copies of themselves by
growing and dividing
central dogma
DNA is replicated, DNA transcribed to RNA translated to amino acids
Bacteria
greatest diversity, commensurate with
their ability to colonize nearly every ecological
niche on the planet
Archaea
prokaryote (different cell wall
structure than bacteria)
*Lack peptidoglycan in the cell wall
- Circular DNA in a single chromosome, but with multiple origins of
replication
Eukaryotes
Eukaryotes form a remarkably
small slice of overall global diversity]
given their close kinship with archaea, some
scientists have proposed combining eukaryotes
and archaea into a single domain
Asgard archaea
ectosymbionts found on cell, all eukaryotes trace back to them
Beggiatoa chemosynthesis
a bacterium that oxidizes H2S to produce sulfur and fix carbon in the dark
Mitochondria generate usable energy from
food molecules
chloroplasts capture energy from
sunlight
Endosymbiont theory
Mitochondria and chloroplasts are thought to originate from the endocytosis of a free-living prokaryote by an anaerobic ancestral eukaryote
*they have their own DNA
*double membrane
*structurally similar to prokaryote ribosomes
*replicate independently
Rough ER
*major site of protein synthesis
*continuous with nuclear envelope receiving mRNA
Smooth ER
*no ribosomes
*lipid synthesis
Golgi apparatus
takes molecules made from ER and packages them in vesicles for exocytosis
Cytosol
concentrated aqueous gel of large/small molecules
*more of water-based gel than liquid
why is comparing genome sequences important
reveals life’s common heritage
what is a way to study humans ethically?
tissue cultures
what is the purpose of model organism
easier to cultivate in a lab and experiment on
Actin
large numbers inside muscle cells, where they serve as a central part of the machinery responsible for muscle contraction.
Microtubules
thickest part of cytoskeleton, hollow tubes that pull apart chromosomes
Intermediate filaments
structural support and anchoring organelles
how big are plant and animal cells?`
5-20 um (micrometre) in diameter