Control That Cell Flashcards
Apoptosis
Cell suicide.
Cancer cells are insensitive to this
The plasma membrane
Hydrophilic head
Hydrophobic
Membrane proteins
Immunological identity
Facilitate transport of some substances
Some are enzymes
Receptors for some hormones
Facilitated diffusion
Carrier protein specific to a substance transports it across the membrane
Eg. Glucose
Eg. Amino acids.
Bulk transport across cell membrane
Into cell= endocytosis
Eg. Phagocytosis
Out of cell= exocytosis
Ribosomes
Are made of protein
Assemble proteins from RNA
Assemble all the proteins needed by the cell
Endoplasmic reticulum
Two types:
Rough and smooth
Rough: studded with ribosomes, produces proteins for transport
Smooth: synthesises lipids and steroid hormones, detoxify some drugs
Golgi apparatus
Stack of membranous sacs
Storage, package and shipping department
Stores proteins in secretory granules
Releases them by exocytosis
Larger in cells that synthesise and export protein
Lysosomes
Secretory vesicle from Golgi Apparatus Isolated environment for potentially dangerous materials Has lots of enzymes to break down -organelles -bacteria -large organic molecules
Cytoskeleton
Made of protein fibres, TWO types 1. Microfilament >structural support. Smallest fibres 2. Microtubules >allow movement within cell. Become spindle fibres in division.make up structure of cilia and flagellum. Taxanes (cancer drug) act on these so they can no longer work
Nucleus
Contains DNA
Directs all cell metabolic activity
23 somatic pairs, one from mum one from dad
Human karyotype
23 somatic pairs
One sex chromosomes (X&Y)
The cell cycle
Stem cell>cycles of division>organ or tissue>death
Damaged or worn out cells> die and others undergo mitosis to replace it
Phases of cell division
Remember here there is apparently only two
Interphase: cell growth
Mitosis: division
Anti-cancer drug methods
Deleting ended pool of nucleotides
Inhibiting needed enzymes in the cell
Hanging DNA structure (unwinding it or breaking the strands)
Rate of cell division
May lead to cancer
Rate is controlled by nucleus> loss of control or checks>cancer
Faster dividing=more chance of cancer(more chance of mistake)
Controlling cell division (2 ways)
Polymerase>checks, edits and executes
Caps> on the ends of telomeres. Shorten with divisions>cancer replication is fast but should not last (teleomeres shorten) BUT unfortunately cancer cells have a highly active enzyme that repairs the caps.
Genes that regulate cell division (3)
Proto-oncogenes
Purpose= promote normal cell growth
Mutation= become oncogenes> uncontrolled cell growth> cancer
Tumour-suppressor genes
Purpose= prevent cell proliferation
Mutation= can’t prevent proliferation>cancer
Apoptotic genes
Purpose= promote or suppress cell death
Mutation= cells won’t kill self if cancerous
Different genes are active in different types of cells
Different cell=different purpose= different protein needed
Genes are inactive while bound to a certain protein
The gene needs to be activated by an enzyme (removed from protein) before the ribosome will read its message
Tissue types (4)
Muscle Epithelial Nerve Connective MENC
Muscle
Voluntary/ skeletal (multi-nucleic)
Long fibres (30cm up to), striated, must be stimulated by nerves, gross motor movement.
Smooth muscle
Lines vessels and organs, squeeze contents, non striated, not voluntary, regulates lumen
Cardiac (mono-nucleic usually)
Striated, cells branch, cell-cell connections at intercalated discs for contraction, involuntary.
Epithelial
Covers external body and internal linings
Two types: simple and stratified
Three functions: absorption, protection and secretion
Simple epithelium
Three classifications: squamous, cuboidal and columnar
Squamous;
Thin and smooth= fast DIFFUSION rate. Lines alveoli, heart vessels,blood vessels etc
Cuboidal;
Secretion, absorption, excretion eg. Line the kidney tubles
Columnar;
Lines many organs with function specific adaptations eg. Microvilli of the stomach or cilia in the trachea.
Stratified epithelium
Several layers of different shapes
Lower layers undergo division to push surface layers up
Prone to cancer> fast division
Can be keratinised (skin, hair, nails)
Or not keratinised (GI tract lining, vaginal lining)
