Cell Biology Flashcards
Mitosis
when a cell splits into two identical copies of the original cell
Meiosis
when cells split into two new cells with half the usual number of chromosomes in order to form gametes for sexual reproduction
Embryonic plant
this is a pluripotent cell which comes from an inner mass of a blastocyst, an early stage pre-implantation embryo.
Pluripotent definition
refers to a stem cell that has the potential to differentiate into any 3 germ layers: endoderm, mesoderm or ectoderm
How does the multinucleate cytoplasm of a fungal hyphae and skeletal muscle bring the cell theory into question?
The cell theory states that cells are the smallest unit of life. The skeletal muscles are long(strips) cytoplasm and fungal hyphae are multinuclear. These do not match the cell theory and are not sufficient in proving the cell theory as they are not strictly made of cells
How does Acetabularium, the giant algal cell that can grow up to 10cm in length and has distinct body parts, disturb the cell theory?
It is a whole organism and is longer than a cell. It is also not made of cells so it goes against the theory that all organisms are made up of cells. Also it has 3 parts rather than 1 unit which doesn’t go with the cell theory
hyphae
main mode of vegetative growth
what are stem cells
they develop into many different types of cells in the body during the early stages of life and growth. They also act as an internal repair system, dividing essentially without limit to replenish other cells. When a stem cell divides, each new cell has the potential either to remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell.
How do stem cells treat diseases?
Stem cell transplant
What are prokaryotes
A microscopic single-celled organism which has neither a distinct nucleus with a membrane nor other specialized organelles, including the bacteria and cyanobacteria
Ribosomes
these are a minute particle consisting of RNA and associated proteins, found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins
what is RNA?
acts as a messenger carrying instructions from DNA for controlling the synthesis of proteins
Features of prokaryotes
- Don’t have a membrane bound nucleus & membranous organelles
- contain DNA and ribosomes within the cell
- Have plasma membranes to protect them from their surrounding environment
- Its cellular components are found within cytoplasm
- Contains 70s ribosome
- All bacteria are prokaryotes
Function of the plasma membrane in Prokaryotes (P)
responsible for controlling what gets in and out of the cell. Proteins located here also help the prokaryote cell communicate with the surrounding environment
Function of cytoplasm in (P)
Contains a complex and functional cytoskeleton which helps the cell to divide and helps maintain its round, plump shape
Function of cell wall in (P)
maintains shape and protects cell from bursting if internal pressure is high
function of plasmid in (P)
additional DNA that can exist and replicate independently
function of the Flagellum/Flagella in (P)
Contains a motor protein which spins the flagella like a propeller enabling movement
function of the Pili in (P)
(attachment) shorter in length, they allow bacteria to adhere to one another of the available surfaces
function of the Sex Pili in (P)
allows for exchange of genetic material(plasmids) by a process called bacterial conjugation
What are polysaccharides
a molecule whose molecules consist of a number of sugar molecules bonded together
what is binary fission
the division of cell in the proctor cells
Steps of binary fission
- cell replicates its DNA
- Cytoplasmic membran elongates, separating DNA molecules
- Cross wall forms; membrane invaginates
- Cross wall forms completely
- Daughter cells
draw the procaryote cell
label also!
Draw the eukaryote cell
label also
function of the Cell Membrane in the (E)
semi-permiable barrier that controls the entry and exit of substances
function of the cytosol in the (E)
The fluid portion of the cytoplasm
function of the nucleus in the (E)
site of the production and assembly of ribosome components
ribosome size in (E)
80s
function of the mitochondria in the (E)
Site of aerobic respiration, which produces large quantities of chemical energy(ATP) from organic compounds
function of the Golgi Apparatus in the (E)
An assembly of vesicles and folded membranes involved in the sorting, storing and modification of secretory products
function of the lysosome in the (E)
site of hydrolysis/digestion/breakdown of macromolecules
function of the peroxisome in the (E)
catalyses breakdown of toxic substances like hydrogen peroxide and other metabolites
function of the centrioles in the (E)
microtubule-organising centres involved in cell division (mitosis/meiosis and cytokinesis)
function of the endoplasmic reticulum in the (E)
a system of membranes involved in the transport of material between organelles
function of the rough ER in the (E)
studded with ribosomes and involved in the synthesis and transport of proteins destined for secretion
function of the smooth ER in the (E)
involved in the synthesis and transport of lipids and steroids, as well as metabolism or carbohydrates
what are the similarities between Eukaryotes and Prokaryotes
Both have a cell membrane
Both contain ribosomes
Both have DNA and cytoplasm
Magnification formula
image/actual
function of the secretory vesicle in Exocrine cell from Pancreas?
release chemicals and proteins from inside the cells to outside the cell wall
Function of the Exocrine cell from Pancreas?
Secrets pancreatic fluid that contains digestive enzymes that pass to the small intestines
Function of the Palisade mesophyll cell?
Site of photosynthesis
the structure of biological membrane does what?
makes cells fluid and dynamic