Chapter 7 Flashcards
All life forms have:
- Proteins
- Nucleic acids
- Carbohydrates
- Plasma mem.
Chromosome
Structures of protein and dna
Plasmid
Super coiled dna structures
Ribosomes
Manufacture proteins
Contain RNA and proteins
Organelles
Mem. bound compartment inside cell that contains enzymes
Cytoskeleton
Protein filaments - maintain cell shape
Plasma mem.
Phospholipid bilayer
inside holds all cell contents - excluding nucleus
Bacterial structure component
peptidoglycan
some outer mem of glycolipids
Flagellum
Used for swimming (movement)
Fimbriae
Used for adhering
Eukaryotic cells divided into
cytosol
Cytosol
fluid between plasma mem and organelles
Compartment advantages
- surface provides location for mem. proteins
- chemical rxn separated
- efficient chemical rxn
- molecule transport within cells
Nucleus
contains chromosomes
enclosed by nuclear envelope
admin centre
Nucleolus
RNA molecule in ribosome are
manufactured
Ribosomes
Manufacture proteins
Endoplasmic Rectilum
portion of nuclear envelope
extends into cytoplasm to form mem. enclosed factory
Rough ER
ribosomes attached to mem.
synthesis of proteins to function in ER or export to diff. destination
interior sac (lumen)
Smooth ER
no ribosomes
makes mem. lipids
Lumen
where proteins undergo folding and processing in RER
Golgi Apparatus
Proteins from RER pass cis –> trans
consists of stacks of mem. sacs called cisternae
Cis
Facing nucleus
receives RER products (cargo)
Trans
Facing plasma mem.
ships cargo
Cisternae
Stacked mem. sacs in Golgi Apparatus
Lysosomes
Recycling centre
hydrolyzes macromolecules
Acid Hydrolase
Digestive enzyme in lysosomes
Endomembrane system
Centre for producing, processing, and transporting proteins + lipids
eg) synthesized in ER, processed in Golgi, shipped to Lysosome
Vacuoles
Contain hydrolase
storage depots
Peroxisomes
Globular organelle
single mem.
originates as vesicle from ER
site for redox rxn
Mitochondria
divides independently
primarily responsible for supplying ATP
2 mem.
Cristae
inner mem. sac within mitochondria
has folds to increase surface area
Mitochondrial matrix
solution enclosed in mitochondria’s inner mem.
Chloroplasts
convert light to energy
2 mem.
divides independently
gains 3rd mem.
Thylakoid
independent network of sac structures
chloroplast’s 3rd mem.
Stroma
region between thylakoid and inner mem. of chloroplasts
Grana
name of thylakoid stacks
Endosymbiosis theory
mitochondria and chloroplast were engulfed by ancestors and formed a symbiotic relationship
Cytoskeleton
protein fibres give cell shape and structural support
involved in moving materials within itself and the cell
organizes all organelles and cellular structures into a cohesive whole
Cell wall
located outside plasma mem.
structural support
rods/fibres composed of carbohydrates run through a stiff matrix made of polysaccarides + proteins
Differential centrifugation
isolate particular cell components and analyze chemical composition
breaking cells apart to create a complex mix + separating parts in a centrifuge
Nuclear envelope
separates nucleus from rest of cell
perforated with pore openings formed by the nuclear pore complex
structure supported by fibrous nuclear lamina
Nuclear lamina
extends through inner and outer mem. connecting the inside of nucleus with cytosol
Nuclear pore complex
Exchange of information between nucleus and cytoplasm
serves as a gate to control passage through the nuclear envelope
Nucleoplasmin
strictly found in nucleus
composed of 5 identical polypeptide subunits each with an amino-acid sequence found at the N-terminus (core) and C-terminus (tail)
a 17 amino-acid chain had to be present to direct nucleoplasmin to the nucleus
17 Amino-acid chain
Nuclear localization sequence (NLS)
Endomembrane system
Pulse-chase
proteins are trafficked through secretory pathways in a highly organized + directed manner
1) proteins enter ER
synthesized by ribosome + processed, one carbohydrate is often added
2) protein exits ER
inside vesicle
3) protein enters Golgi (cis)
processed
4) protein exits Golgi (trans)
in vesicle to plasma mem.
5) protein secreted from cell
Synthesis of proteins
synthesis of proteins to be secreted or embedded in mem. starts in ribosome thats free in cytosol
ER signal sequence
moves growing protein + associated ribosome to RER
typically present in 1st 20 amino-acid and is removed after protein synthesis
ER signal sequence steps
1) protein synthesis begins on free ribosome in cytosol
ribosome synthesizes ER signal sequence, using info mRNA carries
2) signal sequence binds to signal recognition particle (SRP) - complex of RNA + protein
attached SRP causes PS to stop
3) ribosome + signal sequence + SRP moves through RER mem.
attaches to SRP receptor
4) once receptor + SRP connect, SRP is released and PS continues through a channel called Translocon
5) growing protein is then fed into ER lumen and ER sequence is removed
