ch 3 - cellular level of organization Flashcards
structure of plasma membrane
phospholipid bilayer which a hydrophilic head and hydrophobic head
- Also contains steroids, proteins, and carbs
function of plasma membrane
- controls entry and exit of materials
- isolation (separates the inside of the cell from the outside)
- structural support
- sensitivity to environment
glycocalyx
The sticky sugar coat made up of proteoglycans, glycoproteins, and glycolipids.
glycocalyx function
- lubrication and protection
- anchoring and locomotion
- specificity in binding and recognition
what are the 6 types of membrane proteins (IPARRC)
integral
peripheral
anchoring
recognition (identifiers)
receptor
carrier
integral proteins
proteins permanently attached in the membrane
peripheral proteins
proteins temporarily bound to inner or outer surface
- they attach and detach from the cell membrane at different times
anchoring proteins
attach to inside or outside structures and stabilize membrane position
recognition proteins (identifiers)
label cells as normal or abnormal
receptor proteins
binds and responds to ligands
carrier proteins
bind and transport specific solutes through the membrane
selective permeability
Allowing only some substances to get in and out of the cell
what is a nonmembranous organelle
not completely enclosed by a membrane
what is a membranous organelle?
an organelle thats surrounded by its own plasma membrane
What are the 7 main nonmembranous organelles?
cytoskeleton
ribosomes
proteasomes
microvilli
cilia
flagella
centrosomes + centrioles
cytoskeleton
gives the cytoplasm strength and flexibility
what are the 3 cytoskeletal components
-Microfilaments
- Intermediate filaments
- microtubules
centrioles
a pair of cyndrical structures that helps to organize cell division
ribosomes
responsible for making proteins
proteasomes
remove and break down damaged or abnormal proteins that have been tagged with ubiquitin
microvilli
extensions of the plasma membrane that increase the surface area to help absorb extracellular materials
cilia
long slender hair like extensions of the plasma membrane
what are the 2 types of cilia + their fucntions
primary cilia: acts as a sensor
motile cilia: move materials over cell surfaces
flagella
long, whiplike extension of the cytoplasm
ex: found on the tail of sperm
centrosomes
essential for movement of chromosomes during cell division
what are the 6 main membranous organelles?
ER
golgi apparatus
lysosomes
peroxisomes
mitochondria
nucleus
endoplasmic reticulum
network of intracellular membranes that function in TRANSPORTING materials, as well as synthesis and storage,
golgi apparatus
storage, packaging and delivers proteins and lysosomal enzymes
Lysosomes
vesicles filled with digestive enzymes that are responsible for the autolysis of injured cells
peroxisomes
carry enzymes that neutralize potentially dangerous free radicals
mitochondria
responsible for ATP production
nucleus
stores and processes genetic information
active cellular process
- requires energy
- moves substances against the concentration gradient
passive cellular process
- doesn’t require energy
- moves with the concentration gradient (high to low concentration)
examples of passive processes
osmosis
diffusion - simple and faciliated
examples of active processes
endocytosis
exocytosis
pinocytosis
phagocytosis
osmosis
net flow of WATER across a selectively permeable membrane in responses to differences in solute concentration
diffusion
movement of PARTICLES from an area of high to low concentration
tonicity
describes how the concentration of solutes in a solution affects cells
isotonic
equal concentration of solute as the cell
hypotonic
solution has a lower solute concentration than the cell, water ENTERS the cell
hypertonic
solution has higher solute concentration than the cell, water rushes out the cell
endocytosis
imports extracellular materials packaged INTO vesicles
pinocytosis
endocytosis of extracellular fluid
what are 2 examples of endocytosis
pino and phagocytosis
phagocytosis
endocytosis of solid particles
exocytosis
EXPORTS intracellular materials packaged into vesicles
transcytosis
endocytosis on one side of the cell and exocytosis on the opposite side allows substances to pass through the cell
What are the three components of a cell cytoskeleton?
- Microfilaments: smallest filaments composed of the protein actin
- Intermediate filaments: midsize insoluble filaments
- Microtubules: largest of the cytoskeletal filaments, hollow tubes composed of the protein tubulin
histone function
Vital for DNA packaging and regulation within the cell nucleus, ensuring that genetic material is efficiently organized and accessible when needed
mitosis
creates 2 identical daughter cells from 1 cell
meiosis
produces 4 genetically different cells for reproduction
what are the stages of mitosis
prophase
metaphase
anaphase
telophase
prophase
chromosomes condense, the nuclear membrane breaks down, and spindle fibers begin to form.
metaphase
nucleus dissolves and the chromosomes condense and meet in in the center of the cell
Anaphase
the sister chromatids break apart and move to opposite ends of the cell
telophase
the chromosomes reach opposite ends of the cell, and two new nuclear membranes form around them, creating two separate nucleus
protein synthesis steps
- It involves the production of mRNA from a gene on DNA, which then attaches to a ribosome for protein synthesis
- The newly synthesized protein is then modified within the RER and transported to the Golgi apparatus for further processing and packaging
DNA replication
the process of duplicating the genetic material in the nucleus of a cell accurately
dna replication 5 steps
- unwinding dna strands
- Binding of DNA polymerase to exposed nitrogenous bases
- Adding nucleotides to make a complementary strand aka the leading strand
- Assembling a complimentary copy
- Splicing together the 2 dna segments into a strand called the lagging strand
