Cells Flashcards
tissues
group cells that are similar in structure and function
all cells have these three main regions
nucleus
cytoplasm
plasma/cell membrane
what is the function of the plasma membrane
barrier for all cell contents
controls what enters and leaves the cell.
double phospholipid layer
contains cell receptors, proteins, cholesterol and glycoproteins.
tight junctions
bind cells together into leak proof sheets
gap junctions
allow for communication between cells
desmosomes
anchoring junctions prevent cells from being pulled apart
hydrophilic vs hydrophobic
(in plasma membrane) hydrophilic heads - loves water
hydrophobic tails - hate water
microvilli
increase surface area for absorption
selective permeability
let’s some molecules in but not others as a protective measure
passive transport
doesn’t require energy
high concentration to low concentration
with the gradient
active transport
requires ATP
low to high concentrations
up/against the gradient
cytoplasm
cell liquid
located outside the nucleus but inside the plasma membrane
organelles
little organs
metabolic machinery
specific functions throughout the cell
inclusions
chemical substances such as stored nutrients and cell products
cytosol
fluid that suspends other elements
functions of mitochondria
powerhouse of the cell
change shape continuously
provides ATP for cellular energy
carry out cellular respiration so oxygen is used to break down food
ribosomes
sites for protein synthesis
made of protein and RNA
found on rough ER and in the cytoplasm
rough ER vs smooth ER
rough ER - studded with ribosomes, synthesizes proteins
smooth ER - functions in lipid metabolism and detoxification of drugs and pesticides
golgi apperatus
modifies and packages proteins.
(secretory vesicles, lysosomes, cell membrane components)
lysosomes
contains enzymes that digest worn out or unusable materials in the cell
packaged by golgi apparatus and produced by ribosomes
peroxisomes
able to detoxify harmful substances such as alcohol and formaldehyde
membranous sacs of oxidose enzymes
cytoskeleton
provides cell with internal framework
network of protein structures that extend throughout the cytoplasm
what are the three types of elements in the cytoskeleton from smallest to largest?
microfilaments (smallest)
intermediate filaments
microtubules (largest)
centrioles
rod shaped bodies made of microtubules
direct the formation of miotic spindle during division
cellular projections
used for movement
cillia
move materials across the cell structure
located in respiratory system to move mucus
flagella
propel the cell
only flagellated cell in the human body is sperm
nucleus
control center of the cell
contains genetic material (DNA)
nuclear envelope/membrane
consists of a double membrane
ribosomes migrate through nucleic pores in the cytoplasm
nucleoli
sites of ribosome assembly
migrate through nucleic pores
chromatin
thin and stringy
composed of DNA and protein
present when cell is not dividing
condenses to form chromosomes when cell divides
interphase
cells grow and carry out metabolic processes
cell division
cell replicates itself
what are the stages of cell division in order
prophase
metaphase
anaphase
telophase
prophase
centrioles migrate to the poles to direct the assembly of the miotic spindle fibers
DNA appears as double stranded chromosomes
nuclear envelope breaks down and disappears
metaphase
chromosomes align in the center of the cell
anaphase
chromosomes are pulled apart on opposite sides of the cell
cells begin to elongate
telophase
chromosomes uncoil to become chromatin
nuclear envelope reforms around chromatin
spindles break down and disappears
cytokinesis
furrow forms to pinch the cells into two genetically identical daughter cells
begins during late anaphase and completes during telophase
genes
blueprint for one protein
blueprint for all life
fibrous/structural proteins
building materials for cells
globular/functional
act as enzymes, biological catalyst, hormones and antibodies
messenger RNA (mRNA)
carries instructions for building a protein from the nucleus to the ribosomes.
transfer RNA (tRNA)
transfers appropriate amino acids to the ribosomes for building the protein
ribosomal RNA (rRNA)
helps form the ribosomes where proteins are built
what are the steps of protein synthesis?
- as protein is synthesized on ribosome it migrates into the rough ER cistern
- in the cistern the protein folds into its functional shape
- protein is packaged in a transport vesicle
- transport vesicle travels to golgi apparatus for further processing
transcription
transfer of information from DNA base sequences to the complimentary base sequence of mRNA
translation
base sequence of nucleic acid is translated to an amino acid sequence
solution
homogeneous mixture of two or more components
solvent
dissolving medium; typically water in the body
solute
components in smaller quantities within a solution
intracellular fluid
nucleoplasm and cytosol
interstitial fluid
fluid on the exterior of the cell
diffusion
particles tend to distribute evenly within a solution
high to low concentration
simple diffusion
unassisted process
solutes are lipid soluble materials or small enough to pass through membrane pores
osmosis
diffusion of water
highly polar water molecules pass easily across the plasma membrane through aquaporins
carrier meditated facilitated diffusion
protein carrier that is specific for one chemical will bind causing a shape change in the transport process that carries the chemical across the membrane
doesn’t require energy
channel meditated facilitated diffusion
channel within the protein allows ions and larger molecules to pass through the concentration gradient
facilitated diffusion
passive movement of molecules along the concentration gradient
selective process
filtration
water and solutes are forced through membrane by fluid or hydrostatic pressure
pressure gradient must exist so solute containing fluid is pushed through high pressure area to low pressure area
ex: kidneys
hypotonic solution
low solute high water
cells swell and burst
cytosis
water moves from outside the cell to inside the cell
hypertonic solution
high solute low water
cells shrink
water moves from inside the cell to outside the cell
(plasmolysis)
isotonic solution
same level of solute and water
water moves equally in both directions
cell stays the same
(dynamic equilibrium)
