2. Cells and Tissues Flashcards
Write the hierachy of a cell
- cell membrane (phospholipids, cholesterol, proteins)
- nucleus (nuclear membrane, chromosomes (Containing DNA)
- cytoplasm
- cytosol (viscous fluid that suspends other contents, mainly water but also proteins and solutes)
- organelles
- inclusions (chemical substances eg. stored nutrients- not present in all cell types)
define Mitochondria
energy powerhouse for cell
produces ATP
define function of Ribsomes
free - makes proteins for intracellular use
attached to RER- proteins for use in the cell membrane / extracllular use
define function of golgi apparatus
modifies, concentrates / packages proteins and lipids made by ER into membrane bound vesicles
vesicles are stored and then move to plasma membrane for exocytosis as req
define function of lysosomes
garbage collection- digest foreign material, breakdown dead organelles,
define function of Cytoskeleton
- cell scaffolding- network of rods throughout the cytosol that provide structure
- includes microfilaments / microtubules/ intermediate filaments
define function of centrosome
play role in cell division (mitosiss) - anchor point for microtubules to separate centromeres into chromatids
form a base for cilia / microvilli / flagella
define function of cilia
- fine/ hair like extensions on cell surface to move substnaces across cell surface- e.g. dust out of trachea
define function of microvilli
- finger like projections to increase surface area of cell
define function of flagella
- long extension that propels cell for transprot
define function of nucleus
- contains DNA which contains instructions for protein building -which protein to synthesize, and how much.
-also controls cell growth and reproduction (Cell division)
most cells have 1 nucleus, but some have multi (those involved in frequent cell division)/ none (mature erthrocytes)
define function of Nucleic acids
- DNA
genetic material found in nucleus
composed of nucleotides (A,T, G, C)
23pairs of chromosomes (46 in total in each body cell, except sex cells)
RNA- nucleotides (AU,G,C)
involved in protein synthesis (decodes / sends messages on behalf of DNA)
define function of Protein synthesis
made through DNA which provides unique code of nucleotides (A,T,C,G).
MRNA decodes nucleotides and creates complementary code (into triplets) based on AUCG, and transports new seq to ribosomes outside nucleus
tRNA than bring AA which correspond with the mRNA triplets, forming new proteins
Describe structure and function of muscle tissue
specialised myocytes that can contract, to provide movement of bones and substances through hollow organs
3 types
- skeletal muscle (muscle attached to bones)- brings about body movements
- smooth muscle- found in walls of hollow organs (uterus)
- cardiac muscle - found in walls of heart
What are glands
Composed of 1+ epithelial cell that make / secrete particular products called secretions
2 types
- Endocrine: secrete hormones into the bloodstream
- Exocrine: secrete their substance onto a body surface or into a body cavity, most often via a duct; are usually multicellular
- Secretory glands include kidneys/ pancreas / mammary / sebaceous/ sweat /
mucous