2.1 structure and function of a cell Flashcards
what features do all eukaryotic cells have in common.
1-the genetic material—DNA
2-A cell membrane comprise of a phospholipid bilayer
3-Filling the cell interior is the jelly-like cytoplasm
The Nucleus
contains DNA, which stores and
replicates the genetic information of the cell.
Each molecule of DNA in the
nucleus combines with an equal mass of (——) to form a chromosome.
protein
nucleolus
a
non-membrane bound structure in the
nucleus, which contains
RNA and proteins/a denser region containing RNA, protein, and chromatin.
nuclear envelope
a double membrane consisting of two phospholipid bilayers, which
separates the nucleus from the rest of the cell.
nuclear pore complex
a group of proteins
forming openings in
the nuclear envelope
Small particles such as water and ions travel freely through these openings, but the passage of
macromolecules such as RNA is controlled by the nuclear pores
ribosome
a structure
composed of
RNA and proteins,
and responsible
for synthesis of
polypeptides in the
cytosol and on the
surface of the rough
endoplasmic reticulum
endoplasmic
reticulum (ER)
a complex system
of channels and
sacs composed of
membranes enclosing
a lumen; made up of
two parts, the rough ER
and the smooth ER
rough endoplasmic reticulum
ribosome-rich parts
of the ER that look like sandpaper
smooth endoplasmic
Regions of the ER that have no bound ribosomes
what does the smooth ER do?
MAIN(R synthesizes lipids and lipid-containing molecules such as the
phospholipids that make up membranes.)
Smooth ER performs other functions depending
on the type of cell. For example, in the liver, smooth ER helps detoxify drugs and alcohol. In
the testes and ovaries, smooth ER produces testosterone and estrogen.
endomembrane
system
the system
within the cell that
acts to synthesize,
modify, and transport
proteins and other cell
products; includes the
endoplasmic reticulum,
the Golgi apparatus,
vesicles, and the cell
membrane, among
other structures
vesicle
a membrane enclosed sac used for
transport and storage
Golgi
apparatus
s a
stack of curved
membrane sacs that
packages, processes,
sorts, and distributes
proteins, lipids, and
other substances
within the cell; acts
like a “post office” for
the cell
lysosome
a
membrane-bound
vesicle containing
enzymes that catalyze
hydrolysis reactions,
breaking down
macromolecules
catalyze hydrolysis reactions, breaking down macromolecules into smaller molecules that
can be reused by the cell.
vacuole
a large,
membrane-bound
sac in plant cells and
some other cells that
stores water, ions,
macromolecules,
sugars, and amino
acids
chloroplast
an
organelle in the cells
of photosynthetic
organisms in which
light energy from the
Sun is captured and
stored in the form of
high-energy organic
molecules such as
glucose
peroxisome
membrane-bound
sac containing
oxidative enzymes
that break down
excess fatty acids and
hydrogen peroxide,
and participate in the
synthesis of bile acids
and cholesterol
the enzymes in peroxisomes are oxidases
that catalyze redox reactions.
mitochondrion
an
organelle in eukaryotic
cells in which high-energy organic
molecules are oxidized
to obtain energy
basically convert
stored energy into usable energy
cell wall
a rigid layer
surrounding plant,
algae, fungal, bacterial,
and some archaea cells,
composed of proteins
and/or carbohydrates;
gives the cell its shape
cytoskeleton
a network of protein
fibres that extends
throughout the cytosol,
providing structure,
shape, support, and
motility
fluid mosaic model
the accepted model
of the cell membrane,
which is a basic
framework of a semifluid phospholipid
bilayer with a mosaic of
proteins; carbohydrates
may be attached to
lipids or proteins
what are the main factors that affect fluidity in the fluid mosaic model
Temperature
Presence of double bonds in the fatty acid “tails”
Fatty acid “tail” length
The Function of Proteins in a Phospholipid Bilayer
Transport
* Reaction catalysis
Cell recognition
* Signal reception and transduction
