Topic 3 Flashcards
(21 cards)
what does ultra structure of cells mean ?
An image of the cell created in fine detail by an electron microscope
label the ultrastructure of a eukaryotic animal cell
Order of magnitude !
what is meant by one order of magnitude or two orders of magnitude?
one order of magnitude means x10 bigger
two orders of magnitude mean x100 bigger
example-
what are the names of different collections of cells?
in multicellular organisms cells are organised into tissues, tissues into organs, and organs into organ systems - each specialise for a specific function.
In-depth eukaryotic plant cell
Describe structure
e of a nucleus in eukaryotic cell?
Nucleus has a Nucleolus. it is surrounded by a double membrane ( 2 phospholipid bilayers) called envelopes. these envelopes contain pores.
Nucleus contains DNA wrapped around histone proteins in a complex called chromatin and nucleolus which is site of ribosome ( rRNA) production.
Describe the structure of Rough endoplasmic reticulum ?
Rough Endoplasmic Reticulum- a series of flattened sacs closed by a membrane with ribosomes on the surface. RER folds and processes proteins made on the ribosomes; often located close to the nucleus.
Describe structure of Smooth Endoplasmic reticulum ?
Smooth Endoplasmic Reticulum- System of membrane bound sacs -SER processes and produces lipids
describe the structure and function of Golgi apparatus?
a series of fluid filled, flattened and curved sacs with vesicles surrounding the edges. The Golgi apparatus MODIFIES PROTEINS ( eg adds a carbohydrate group). produces vesicles for PACKAGING of proteins and budding from the RER. also involved in CONCENTRATION of proteins.
also produces lipids . it also produces lysosomes
Describe the structure of Mitochondria ?
Usually oval shaped and bound by a double membrane called the envelope. the inner membrane is folded to from projections called Cristae, with a fluid matrix on the inside containing the enzymes needed for cellular respiration.
Centrioles definition?
Hollow cylinders containing a ring of microtubules arranges at right angles to each other. centrioles are involves in cell division
Ribosomes definition ?
Composed of two subunits. the site of protein synthesis
Lysosome definition ?
vesicles, containing digestive enzymes, bound by a single membrane
Protein trafficking
proteins are produced on the ribosomes,
proteins produces on the ribosomes (which were eon the RER) are folded and processed in the RER
proteins are then transported for the RER to the Golgi apparatus in vesicles
they are then modified eg carbohydrate group added to the protein forming a glycol protein
protein is then transported in vesicles to required areas of cell, some proteins leave via exocytosis for extracellular enzymes
label the structure of prokaryotic cell vs animal eukaryotic cell
compare animal and
plant cell
What is the structure and function of the Golgi apparatus
it is a membrane bound organelle in eukaryotic cells made up of flattened sacks called cisterna.
its fiction is to modify proteins e.g adds a carbohydrate group.
Production of vesicles for packaging of proteins.
concentration of proteins - tries to get as many proteins in vesicle as possible.
what is the meaning of locus and loci according to 3.8 ?
Location of genes on a chromosome
describe gene linkage the understandable version not mark scheme version
Genes are located on chromosomes.
During meiosis, homologous chromosomes pair up and can exchange segments in a process called crossing over.
If two genes are on the same chromosome, they are said to be linked.
The closer together two genes are, the less likely crossing over will separate them — so they are more likely to be inherited together.
