Biology - Cell biology (MYP5)

Stem cells

have the ability to differentiate to multiple cell types

Similarity between DNA and RNA

both have nitrogenous bases

DNA

is double stranded (is more structured), deoxyribosome backbone function

RNA

has one strand, ribosome backbone function

Differentiation (stem cells)

process of specialising (genes are activated/inactivated)

Potency (stem cells)

relates to how many different cells a stem cell can turn into

Self-renewal (stem cells)

the stem cells that can replenish themselves through an equal cell

Labile epithelial cells (always replenishes itself)

skin cells, GI trackt (intestine), uterus

Stable cells (do not replenish as often, but can)

liver, kidneys, smooth muscle

Permanent cells (cannot replenish themselves)

neurons, cardiac tissue, skeletal muscle

Cell division

allows growth of the organism and allows for more cell differentiation to occur - cells need to regularly replace dead, damaged or infected cells

Membrane

allow cellular compartments to have different conditions, can act as a barrier and are mainly made of phospholipids

Permeability

how well something can let something through

Non-permeable

lets none through

Semi-permeable

lets some through

Permeable

lets all through

Diffusion

particles/molecules moving from a region of high concentration to a region of low concentration

Active transport

low concentration--->high concentration (against gradient and does require ATP)

Passive transport

high concentration--->low concentration (along gradient and does not require ATP)

Hypertonic

higher relative solute concentration

Hypotonic

lower relative solute concentration

Isotonic

same relative solute concentration

Gene

a sequence of DNA (nucleotide base) that code for a trait

Allele

variant of the same gene

Zygote

first diploid cell

Meiosis

sex cell division