Chapter 2 Flashcards
what Luca means
last universal common ancestor
properties of all cells (4)
- all cells have intracellular composition different from the outside
1. metabolism (cells take up nutrients,transform them, and expelled waste
2. growth (nutrients from the environment are converted into new cells materials to form new cells)
3. evolution (cells evolve to display new properties)
- all cells have intracellular composition different from the outside
two aspects of the metabolism (a propriety of all cells)
- genetic
2. catalytic
4 properties of some cells
- differentiation (some cells can form new cell structuressuch as a spore)
- communication (interact with each other by chemical messenger)
- genetical exchange (by different mecanisms)
- motility (capable of cell propulsion)
definition of metabolism
generation of precursors of macromolecules (sugars, amino acids, fatty acids..)
the bigger you get….
the relatively less surface you have
what are the limits in diameter
0,5 um- 750 um
3 roles of the membrane
- permeability barrier
- protein anchor
- energy conservation
major phospholipids in the membrane found in the bacteria
phosphatidylethanolamine
in the structure of the phospholipids, what the archaea doesn’t have compare to the bacteria/eukaryote
the double bond (ether bond instead of the ester)
membrane of archea is bi or monobilayer
monolayer
type of sterol in animal cells, fungi and plant cells
animal: cholesterol
fungi: ergosterol
plant and some protozoans: stigmasterol
in bacteria + archaea, sterol are majority absent so the membrane is stabilize by what
hopanoid
storage structure present in bacteria but not eukaryote
plasmid
the place DNA is is found in :bacteria, eukaryote
bacteria: cytoplasm
eukaryote: nucleus
robosome is composed of (2)
ribosomal RNA and proteins
role of ribosome
translate mRNA into amino acids chains in order to form proteins
where are the robosomes in bacteria and eukaryote
bacteria: free in the cytoplasm or attached to the cytoplasmic membrane
eukaryote: free in the cytoplasm or bound to the endoplasmic reticulum
number of subunits in the ribosome of prokaryotes
70S (30S + 50S) subunits
number of subunits in the ribosome of eukaryotes
80S (40S + 60S) subunits
what are organelles
compartiment made of membranes (phospholipids bilayer and proteins)
cellulose (polymer of glucose) is the composition of the cell membranes of which species (3)
plants, algae and some fungi
cell wall molecules of fungi
chitin (polymer of N-acetylglucosamine
characteristics of euchromatin (2)
loosely packed, actively transcribed
characteristics of heterochromatin (20
densely packed, low level of transcritption
DNA wraped around _____ which form loops of DNA called ______. These ____ coil and stack together to form fibers called ______. These ones in turn form larger loops and coils to form _______
histones
nucleosome
chromatin
chromosome
what is formed during translation
ribosome-mRNA complex
what happens to the ribosome-mRNA complex in the case of cytoplasmic proteins
they stay free in the cytoplasm
what happens to the ribosome-mRNA complex in the case of membrane proteins, secreted proteins or vesicular proteins
it is directed to the ER
what is the endoplasmic reticulum
a system of membranous channel, the membrane is composed of a bilayer of phospholipid
characteristics of rough ER
studded with ribosomes
important for protein synthesis
characteristics of smooth ER
no ribosomes, involved in synthesis of lipid
proteins destined for secretion are synthesizedd by what
ribosomes attached to the endoplasmic reticulum
what is the Golgi body + role
a set of membrane compartiments involved in further processing of proteins and their distribution. Proteins are packaged in vesicles and transported to where they are required
Golgi body- an example is the lysosomes (what is it + function)
internal vesicles that contains hydrolytic enzymes required for degradation of material brought brought in by phagocytos and endocytos
role of mitochondria + what they are able to synthesize
production of the majority of the ATP required by the cells
able to synthesize some of their own proteins (the other ones are imported from the cytoplasm of the cell)
characteristics of the outer membrane of the mitochondria
many porins proteins, makes this membrane permeable to small molecules
characteristics of the inner membrane of mitochondria
75% proteins, 25% lipids transports proteins (regulated transport), enzymes,cytochromes, ATPase
composition of the matrix of the mitochondria (3)
enzyme (citric acid cycle), DNA, ribosomes (70S)
3 characteristics of stroma and it is the site of what
circular DNA
70S ribosomes
enzymes of the Calvin cycle
stroma is the site of the Calvin cycle: assimilation of CO2, biosynthesis
what is thylakoid
closed system of interconnecting sacks and tubules
what thylakoids contains
enzymes and pigments that harvest light energy and the membrane-bound ATPases that use this energy to produce ATP
3 examples of intermediaire filament
keratin, desmin, vimentin
name of the 2 proteins that attach to vesicles or organelles and walk on microtubules to transport their cargos to where they are required
kinesin and dynein
role of microtubules
microtubules serve as highways for the transport of organelles and vesicles around the cytoplasm
structure of actin filament
strands in double helix
structure of intermediaire filaments
fibers wound into thicker cables
structure of microtubules
hollow tube
4 role of actin filament
- maintain cell shape by resisting tension
- move cells via muscle contraction or cell crawling
- divide animal cells in two
- move organelles and cytoplasm in plants, fungi and animals
2 roles of intermediate filaments
- maintain cell shape by resisting tension
2. anchor nucleus and other organelles
6 roles of microtubules
- maintain cell shape by resisting compression (push)
- move cells via flagella or cilia
- move chromosome during cell division
- assist formation of plate during plant cell division
- move organelles
- provide track for intracellular transport
how does the dynein arms create movement
they slide the doublets past each other, creating movement
2 major differences between membranes of bacteria and archaea
- bacteria/eukaryotes: ester linkages and fatty acids
- archaea: ether linkages and isoprene units to form a phytanyl group, not a fatty acid
4 membrane proteins
transporters
enzymes
sensors
adhesins
