Cell Biology Primer - Flashcards

Name the 6 levels of organisation

organelle → cell → tissue → organ → organ system → organism

key characteristics of an organelle

inside a cell; there are various types with different functions

key characteristics of a cell

all living organisms have cells; cells are the building blocks of life

key characteristics of a tissue

cells are organised into tissues that do certain jobs; many different types of cells can work together to make a tissue function

key characteristics of an organ

has a more general function; made up of tissue(s)

key characteristics of an organ system

organs work together to fulfil specific roles in the body

key characteristics of an organism

comprised of multiple different organ systems

what do cells do (jobs)?

* detecting
* signalling
* digesting, absorbing or transporting
* fighting infection
* moving

what do cells do (processes)?

* make things
* break things down
* change membrane voltage
* secrete/transport things
* detect things

features of the cell membrane

a thin coat of phospholipids that surrounds the cell and controls what enters and leaves the cell

features of cytoplasm

the material inside the cell membrane; includes watery cytosol and other cell structures (except the nucleus if present)

what is cytosol made of?

* water (\~70%)
* Ions, e.g. Na+, Ca2+
* small molecules, e.g. ATP, NADH, glucose
* amino acids
* soluble proteins, e.g. calmodulin, protein kinase C

features of the cytoskeleton

consists of filaments and tubules that crisscross the cytoplasm and help maintain the cell’s shape

features of the nucleus

contains most of the cell’s DNA; acts as the control centre of the cell

features of DNA

a nucleic acid found in cells; contains the genetic instructions for making proteins

features of ribosomes

structures found in all cells; the site of protein synthesis

features of endoplasmic reticulum

an organelle that helps make proteins and lipids; transports proteins in the cell

features of the Golgi apparatus

an organelle that modifies, sorts, and packages proteins for secretion out of the cell/use in the cell

features of lysosomes

organelles that use enzymes to break down molecules so their components can be recycled

features of mitochondria

organelles that use energy stored in glucose to make ATP (which cells can use for energy)

what is ATP?

adenosine triphosphate

what does ATP do?

* Drive reactions (e.g. protein synthesis)
* muscle contraction and dilation
* move molecules against gradients
* transport proteins or organelles around the cell
* move microtubules to allow cells to craw; or processes to move
* produce heat to maintain body temperature

describe the process of making a protein

transcription → splicing → export → translation → folding → protein

what is alternative splicing?

RNA-binding proteins chop out introns and stick exons together; different RNA-binding proteins in a given cell stick different exons together; get lots of different proteins made from a single gene

what are the four protein structures?

* amnio acid (primary structure)
* α-Helixes (secondary structure)
* polypeptide chains (tertiary structure)
* complex of protein molecule (quaternary structure)

examples of how different cells express different proteins

* red blood cells express haemoglobin (tetramer)
* pancreatic beat cells express insulin (hexamer)
* neurons express ion channels
* muscle cells express myosin and actin

ATP synthesis

* when cells need energy they break down ATP into ADP and inorganic Phosphate (Pi) which releases energy
* ATP is synthesised via substrate-level phosphorylation and oxidative phosphorylation