cells Flashcards
what is tissue
- group of cells that do a specific job - tightly bound with junctions to stop bacteria entering the body
- organisation of neurons effects the job they’re doing
what is an organ
- those tissues are organised to make an organ.
- organs do a more generalised job eg brain = infomation processing → but then diff parts of brain specialise in diff things
what is an organ system
- combination of organs, eg digestive system
OR
- brain + spinal cord + nervous system
an organism
centrel organism doesn’t work alone, combination of organ systems
the levels of organisation
- organelle
- cell
- tissue
- organ
- organ system
- organism
what do cells do ?
5
- detecting
- signalling
- digesting, absorbing or transporting
- fighting infection
- moving
detecting
what do cells do ?
sensory neurons, pancreatic beta cells
signalling
what do cells do ?
neurons, endrocrine cells
digesting, absorbing or transporting
what do cells do ?
epithelial cells, red blood cells, exocrine cells [secrete sweat, tears etc]
fighting infection
what do cells do ?
leukocytes
moving
what do cells do ?
cardiac muscle, smooth muscle or skeletal muscle cells
what do cells do [processes]
5
- make things
- break things down
- change membrane voltage
- secrete/transport things
- detect things
make things
what do cells do [processes]
- proteins
- lipids
- mRNA
- DNA
- ATP
break things down
what do cells do [processes]
- glucose
- proteins
- carbohydrates
change membrane voltage
what do cells do [processes]
especially neurons, muscle cells
secrete/transport things
what do cells do [processes]
- neurotransmitters, glucose, digestive enzymes, sweat, ions
detect things
what do cells do [processes]
- light
- sound
- levels of diff molecules **eg ATP, calcium **
what is the cell membrane
- a thin coat of phospholipids that surrounds a cell and controls what enters and leaves the cell
- inside and outide of the cell are different
- proteins in the membrane that controls what comes in and out
what is cytoplasm
- the material inside the cell membrane, including the watery cytosol and other cell structures except the nucleus if one is presnt
- contains diff organelles, and cytosol
cytosol contents
5
- Water (~ 70%)
- Ions, e.g. Na+, Ca2+
- Small molecules, e.g. ATP, glucose
- Amino acids (building blocks for proteins)
- Soluble proteins
what is the cytoskeleton
- network of filaments and tubules that crisscross the cytoplasm and help maintain the cell’s ahep
what is the nucleus
- an organelle that contains most of their cell’s DNA and acts as the control center of the cell
- controls what gense are expressed and proteins get made
what is DNA
- is a nucleic acid found in cells
- contains the genetic instructions that cells need to make proteins
what are ribsomes
- structures found in all cells that are the site of protein synthesis
types of proteins
7
- antibodies
- contractile proteins, e.g. myosin
- enzymes e.g. ATP synthetase [ which makes ATP, very imp.]
- hormonal proteins e.g. insulin
- structural proteins e.g. collagen
- storage proteins e.g. ferritin
- transport proteins e.g. haemoglobin,cytochromes, glucose transporters
what is a protein
- a chain of amino acids
- the order of amino acids is coded by DNA
what does haemoglobin do
binds oxygen and sends round body
different cells express diff proteins
3 examples
- red blood cells - haemglobin
- pancreatic beta cells - insulin
- neurons - ion channels
what is the endoplasmic reticulum
an organelle that helps make proteins and lipids and transports proteins in the cell
what is the golgi apparatus
an organelle that modifies, sorts and packages proteins for secretion out of the cell, or for use within the cell
what are lysosomes
organelles that use enzymes to break down molecules so their components can be recycled
* eg recycyling centre of the cell
what are mitochondria
organelles that use energy stores in glucose to make ATP, which cells can use for energy
what does ATP do?
6 uses
- 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 crawl or processes to move
- Produce heat to maintain body temperature
what are glia
brain cell types
what are the types of glia
3
- astrocytes
- oligodendrocytes
- microglia
what are astrocytes
- star shaped
- multiple processes in the brain, processes that are close to synapses
- Important in controlling neurotransmitters levels.
- talk to blood vessels
- move molecules around fluid around the cells
what do oligodendrocytes do
wrapping myelin sheaths [helps neuron transmission] around axons
what are microglia
brain’s resident immune cell, look for damage, eat dead cells, protective of brain, fight infection
