week 1 CTL Flashcards
Discuss the differences between prokaryotic and eukaryotics cells
Prokaryotic cells are thought to be the more primitive cell type. They have a definding plasma membrae, their DNA is not contanied in a nucleus and its intracellular environment lacks organisation/compartmentalisation into organelles (membrane bound). Include BACTERIA AND ARCHAENS
Eukaryotic cells: Have an intracellular environmental that is organised into compartments/organelles which allow for optimal functional environments for various cellular processes. DNA is contained within nucleus.
What are the four cell theories and what do they mean?
1) CELLS ARE THE BASIC FUNCTIONAL UITS OF LIVING ORGANISMS this means all living things are made up of either prokaryotic or eukaryotic cells
2) CELLS ARE ALIVE this means that cells are not static, they are growing, adapting and reproducing. This process is important in understanding physiology the normal growth, development and differentiation of cells VS pathophysiology the abnormal function of cells. It is also important to note that while cells have the same DNA they are have undergone differentiation and are highly specialised to exhibit different characteristics that enable them to carry out their various function
3) THE PRINCIPAL OF COMPLEMENTARITY OF STRUCTURE AND FUNCTION This means that structure and function are intrinsically linked at a cellular, tissue, organ or system level. Structure dictates function!
4) CELL CYCLE This means that cells have their own life cycle and reproduce through Mitotic cell division. Cells are not static they are continually changing. Most cells reproduce themselves with like cells but some cells can develop into STEM cells which produce other types of cells allowing for adaptiation of tissues (osteoprogenitor cells). Turn over rates of cells vary from cell to cell e.g. neurons are seperated from the blood and are in a very controlled environment not turned over often VS epithelia frequent turn over.
What are the phases of MITOSIS
Interphase: period between cell divisions
G1: metabolically active cell replicates cytosolic components, rapid cell growth
S: DNA replication and centrosome replication commence
G2: continued growth, enzyme and protein synthesis and centrosome replication complete
P: Prophase is when the chromatin fibres condense to form chromatids. Centrosomes migrate to opposite poles and mitotic spindle formed.
M: Identical sister chromatids line up along the metaphase plate that forms with their centromeres align at the plate.
A: Centromeres split and identical sets of chromosomes move to opposite poles of the cell.
T: Nuclear envelope and nucleolus re appears, mitotic spindle disappears, chromosomes revert back to chromatin form
Cytokinesis: occurs during anaphase, Contractile ring forms making a cleavage furrow then the cytoplasm is split into two equal portions
compare mitosis and meisis
Cell type: Mitosis - somatic Meiosis - gametes
Number of cell divisions: Mitosis - 1, Meisosis 2
Copy DNA: Mitosis during interphase S in both
Stages: Mitosis has interphase, PMAT cytokinesis
Meisosis has Interphase, PI and P2, M1 and M2, A1 and 2, T1 and 2
Tetrads formed? In meisosis not mitosis
Number of cells formed: Mitosis is two cells formed (diploid) , Meiosis 4 cells fromed (haploid)
what are the major targets for antimicrobial therapy
1) inhibits synthesis of bacterial cell wall e.g. penicillin
2) Inhibits protein synthesis e.g. tetracyclines
3) Inhibits nucleotide synthesis e.g. sulfonamides
4) alters bacterial cell membrane function e.g. polymyxin
