atoms, molecules, cells

differentiation

transformation of an unspecialised cell to one of the 4 types of specialised cell

3 types of muscle cell

1. skeletal

2. cardiac

3. smooth

skeletal muscle

attached to other structures, bone or skin

under voluntary control

cardiac muscle

only found in heart, specialised to pump blood

involuntary control

smooth muscle

surround many tubes in the body (veins, artery, etc)

involuntary control

4 major categories of specialised cells

1. muscle

2. epithelial

3. connective-tissue

4. neurons

all muscle cells are specialised to…

generate force

neuron cells are specialised to…

initiate, integrate, and conduct electrical signals to other cells

neuron-neuron

electrical signals to pass on signals

neuron - gland

secrete chemical signal

neuron - muscle

contraction

a collection of neurons

nervous tissue

A epithelial cell

B tubular lumen

C blood vessel

D glucose molecule
E baso lateral membrane
F tight junction
G apical membrane
H basement membrane

4 categories of epithelial cell shapes

1. columnar - elongated

2. squamous - flattened

3. ciliated - specialised function

4. cuboidal - cube shape

nerve

neurons packaged together with connective tissue

tight junction

epithelial cell can form selective barriers regulating the exchange of molecules

connective tissue

connect, anchor, and suppport the structures of the body

5 types of connective tissue

1. loose connective tissue

2. dense connective

3. blood

4. adipose

5. bone and cartilage

loose connective tissue

found in the loose meshwork of cells and fibers underlying most epithelial layers

dense connective tissue

tough, rigid tissue that makes up tendons and ligaments

why is blood a connective tissue (2)

• blood cells have same embryonic origin as other connective tissue

• blood connects tissues / organs by delivering nutrients, removing waste, and transporting chemical signals

ECM (extracellular matrix) (5)

• formed by some connective tissue

• contains the extracellular fluid

• consists of a mixture of proteins, polysaccharides, and sometimes minerals

• provides scaffold for extracellular attachments

• regulates activity, differentiation, migration and growth by transmitting info via chemical messengers

the proteins in the ECM

1. rope like fibres - collagen

2. rubberband like fibers - elastin

Organs (4)

• composed of atleast 2 of the 4 types of tissue

• cells can be arranged in different pattens (sheets, tubes, laters)

• can be divided into functional unit, eg nephron of kidney

• can be grouped into organ systems

epithelial cell (2)

• forms barriers

• selectively absorbs and secretes ions and organic molecules

extracellular fluid

• fluid in blood and surrounding cell

interstitial fluid (2)

• contained in interstitium

• extacellular fluid around and between cells

exchange between bodily fluid compartments (4)

The intracellular fluid (ICF) is conditioned by…

the interstitial fluid (ISF), which is “conditioned by”

the plasma, which is “conditioned by”

… the organ systems it passes through

Homeostatis definition

• state of reasonably stable balance between physiological variables

• Dynamic constancy - variables unfixed, fluctuate with respect to time within a reasonable range

Covalent bonds

• between atoms in a molecule

• when electrons transfer energy from the outer energy shell of one atom to that of another

polar covalent bonds (4)

• electrons not shared equally among pair of atoms

• one atom has slightly negative charge, one has slightly positive

• the most electronegative atom in the pair attracts the electron more, so they spend more time with it

• more water soluble, readily dissolve in blood

non-polar covalent bonds (5)

• atoms have similar electronegativities

• electrons are equally or nearly equally shared

• less soluble in water

• when in fluids eg blood, associate with polar molecule as a carrier to prevent nonpolar molecule coming out of solution

• eg cholesterol is carried out by lipoproteins

hydrogen bonds

• electrical attraction

• very weak, but when present in large numbers, important role in molecular interactions and in determining the shape of large molecules.

electronegativity

the ability of an atom to attract an electron

ampipathic molecules (5)

• have polar / ionised region on ends

• non polar region on opposite end

• polar, hydrophilic region on surface

• hydrophobic non polar ends orientated towards interior

• form clusters

lipids (5)

• linked by nonpolar covalent bonds

• are nonpolar molecules, low solubility in water

• some are signalling molecules

• some are in cellular membranes

• some provide energy

4 types of lipid

• steroids

• phospholipids

• fatty acids

• triglycerides

triglycerides (5)

• majority of lipids in body

• glycerol covalently bonds to 3 fatty acids

• in great quantities in adipose tissue

• found in all cells

• in cellular membranes, including intracellular organelles

fatty acids (5)

• hydrocarbon chain with carboxyl group

• saturated: only single bonds

• unsaturated: atleast 1 double bond

• 1 double bond: monounsaturated

• more than 1 double bond: polyunsaturated

phospholipids (4)

• 2 fatty acids, 1 glycerol, 1 phosphate molecule

• small polar or ionised nitrogen containing molecule attached to phosphate

• polar head

• nonpolar hydrophobic core from fatty acids

steroids (3)

• skeleton: 4 interconnected rings of carbon atoms

• not water soluble

• eg cholesterol, cortisol, sex hormones

proteins (4)

• 50% of organic material in the body

• carbon, hydrogen, oxygen, nitrogen, and small amounts of other elements, notably sulfur

• macromolecules

• subunit monomers are amino acids

amino acids (3)

• every amino acid except proline has amine and carboxylic acid bonded to terminal alpha C

• 20 different amino acids

• essential amino acids: must be obtained by diet

energy currency in the body

ATP

4 major types of molecules

carbohydrates, lipids, proteins, nucleic acids