Lesson 1 - Introduction (after break hehe) Flashcards
new genes are generated from __ __
preexisting genes
introduces a piece of DNA from the genome of one cell to that of another
Horizontal (intercellular) transfer
more than __ gene families are common to all 3 domains of life
200
Two fundamentally different classes of cells
- prokaryotic cell
- eukaryotic cell
- does not have internal organelles surrounded by a membrane
- most functions take place in the cytoplasm
prokaryotic cell
has distinct membrane-bound organelles that allow different parts of the cell to perform different functions
eukaryotic cell
Two distinct kingdoms of prokaryotic cells
- eubacteria
- archaea
size of prokaryotes
1-2 μm
genome of prokaryotes
single circular DNA
additional small circular DNA molecules in prokaryotes
plasmids
Two types of membrane bound structures
- single membrane
- double membrane
single membrane organelles
- endoplasmic reticulum
- vacuole
- lysosome
- peroxisome
double membrane organelles
- nucleus
- mitochondrion
- chloroplast
non-membrane bound organelles
- ribosome
- proteasome
- nucleosome
- centriole and microtubule organizing centers (MTOC)
- cytoskeleton
- flagellum
site of assembly of ribosome subunits
nucleolus
passage for RNA and proteins
nuclear pore
- network of membranes related through direct physical contact or by vesicles
- divides the cell into structural and functional compartments
endomembrane system
inclusions of the endomembrane system
- nuclear envelope
- endoplasmic reticulum
- golgi complex
- transport and secretory vesicles
- lysosomes
- peroxisomes
- vacuoles
- plasma membrane
serves important functions particularly in the synthesis, folding, modification, and transport of proteins
endoplasmic reticulum (ER)
2 regions of the endoplasmic reticulum (ER)
- rough endoplasmic reticulum (RER)
- smooth endoplasmic reticulum (SER)
- synthesizes proteins
- extension of the outher nuclear membrane
- ribosomes attached to the membrane
- protein products are wrapped in transport vesicles that bud from the ER
rough endoplasmic reticulum
protein products are wrapped in __ __
transport vesicles
- involved in the synthesis and storage of lipids, including cholesterol and phospholipids, which are used in the production of new cellular membrane
- detoxify
- phospholipid biosynthesis
smooth endoplasmic reticulum
- flattened stack of sac-like membranes that are scattered throughout the cytoplasm
- sorts, modifies, packages cellular products and secrete them out to their destinations
golgi bodies
flattened stack of sac-like membranes
cisterna
name of golgi bodies in plants
dictyosomes
receiving side of golgi body
cis face
- digests macromolecules, cellular debris, old organelles and foreign substances
- produced by the golgi complex
- contain digestive (hydrolytic) enzymes – ‘demolition sites’ or ‘suicidal bags’
lysosomes
releasing side of golgi body
trans face
what do lysosomes contain
digestive (hydrolytic) enzymes
- detoxify toxins and free radicals, breakdown fats, produce bile salts
- contains enzymes produced by cytoplasmic ribosomes
peroxisome
where are peroxisomes found
liver cells
ubiquitous heme enzymes that catalyze the removal of hydrogen peroxide
- Catalases
- peroxidases
- storage of water, ergastic substances, inclusions, etc
- single membrane organelle separated from the cytoplasmic contents by tonoplast
vacuole
membrane that surrounds the large vacuole in a mature plant cell
tonoplast
vacuole in animals
small but several
vacuole in protists
contractile vacuoles
vacuole in plants
one large central vacuole
- ATP production via cellular respiration (energy extraction process)
- “powerhouse of the cell”
- sausage-shaped organelle about the size of a bacterial cell
- has its own set of circular DNA and may divide by simple fission
mitochondrion
parts of the mitochondrion
- outer membrane
- intermembrane space
- inner membrane folded into crista
- matrix
- a double phospholipid membrane that separates the inside of the mitochondria from the rest of the cell
- helps define the inter-membrane space between itself and the mitochondrial inner membrane
mitochondrial outer membrane
compartment accommodates many proteinaceous factors that play critical roles in mitochondrial and cellular metabolism, including the regulation of programmed cell death and energy conversion
intermembrane space
- functional barrier to the passage of small molecules between the cytosol and the matrix
- maintains the proton gradient that drives oxidative phosphorylation.
inner mitochondrial membrane
- folds in the inner mitochondria membrane
- folds increase the surface area of the inner membrane where energy production occurs.
Cristae
- inner space surrounded by the mitochondrial inner membrane, which contains several proteins, such as enzymes involved in the tricarboxylic acid cycle, fatty acid oxidation, amino acid degradation, and other biochemical reactions
mitochondrial matrix
- food production via photosynthesis (energy-storing process)
- energy-capturing centers in photosynthetic eukaryotes
- circular DNA; may divide by simple fission
chloroplast
parts of the chloroplast
- outer membrane
- inner membrane
- thylakoid sacs - granum
- stroma
site of photosynthesis
thylakoid
stack of thylakoids
granum
like that of mitochondria, contains porins and is therefore freely permeable to small molecules
outer membrane of the chloroplast envelope
impermeable to ions and metabolites, which are therefore able to enter chloroplasts only via specific membrane transporters.
inner membrane of chloroplast
other organelles
- plastids
- glyoxysomes
organelles containing pigments and food materials
plastids
Three types of plastids based on pigments contained
- chromoplasts
- leucoplasts
- chloroplasts
- colored plastids containing carotenoids
- present in fruits, flowers, and leaves
chromoplasts
colorless plastids which store food materials
leucoplasts
different types of leucoplasts
- amyloplasts
- aleuroplasts
- elaioplasts
store starch
amyloplasts
store proteins
aleuroplasts
store lipids
elaioplasts
carotenoids in chloroplasts
- carotenes
- xanthophylls
green-colored plastids containing chlorophylls and carotenoids (carotenes and xanthophylls)
chloroplasts
- microbodies that store and covert fats into carbohydrates
- used in seed germination
glyoxysomes
temporary, non-membranous structures in plants
ergastic substances
ergastic substances inclusions
- food reserves
- secretory products
- excretory products
- mineral crystals
food reserves in plants
- starch
- protein
- oil
secretory products in plants
- nectar
- pigment
- enzymes
excretory products in plants
- alkaloids
- resins
- latex
- tannins
mineral crystals in plants
- cystoliths
- raphides
- druses
cystoliths
calcium carbonate
raphides
calcium oxalate
- supports the shape of the cell, anchors organelles, cell movement
- dense network of protein fibers present in 3 different kinds
cytoskeleton
Three differen tkinds of cytoskeleton
- microfilaments
- intermediate filaments
- microtubules
- structure and support in the cell
- involved in separating cells during cell division, allowing for motility and changes in cell shape.
- cell motility
microfilaments
- function primarily as flexible intracellular tendons (analogous to nylon rope)
- prevent excessive stretching of cells that are subjected to external or internal physical forces
- provide internal guy-wire to resist pulling forces
Intermediate filaments
- help support the shape of a cell
- help chromosomes move during cell division
- help small structures called cell organelles to move inside the cell.
Microtubules
- anchor and assemble microtubules
- give rise to spindle fibers during cell mitosis
- found in animals but not in plants and fungi
centriole
- cell movement
- propel substances across a cell’s surface
- consists of microtubules
- anchored in the cell by a basal body
- short but numerous
cilium
high speed locomotives that run along microtubular tracks in eukaryotic cells
- kinesin
- dynein
motor protein that moves vesicles to the cell’s periphery
kinesin
motor protein that moves vesicles to the cell’s interior
dynein
cellular junctions
- occluding
- anchoring
- communicating
command center of the cell
nucleus
the nucleus contains the genetic material organized into __
chromosomes
complex nucleoprotein material
chromatin
parts of the nucleus
- nuclear envelope
- nuclear pore
- nucleoplasm
- nucleolus
separates the contents of the nucleus from the cytoplasm and provides the structural framework of the nucleus.
nuclear envelope
small channels in the nuclear membrane that facilitate the selective and directional transport of RNA and proteins between the nucleoplasm and the cytoplasm of the cell
nuclear pore
- type of protoplasm that is composed of thick fluid and constitutes chromatin fibres made up of DNA and usually found in the nucleus of the eukaryotic cells
- fluid contains primarily water, dissolved ions, and a complex mixture of molecules.
Nucleoplasm
- spherical structure found in the cell’s nucleus whose primary function is to produce and assemble the cell’s ribosomes
- where ribosomal RNA genes are transcribed.
nucleolus