Bio+chem+phy Flashcards
What is Avogadro’s number?
6.02 x 10^23
What does Avogadro’s number tell us?
the number of particles in a mole of a substance
Which isotope are all other particles compared to when determining their relative mass?
Carbon - 12
What order do the orbitals fill in (up to the end of the third energy level)?
1s2s2p3s3p4s3d
What order do we write the orbitals when they have electrons in them?
1s2s2p3s3p3d4s
What are the properties of metals?
Good conductors of heat and electricity, high melting and boiling points, malleable, ductile
Describe the structure of a metal
A giant lattice with layers of positive ions surrounded by delocalised electrons
Define the term ‘first ionisation energy’
The energy required to remove one mole of electrons from one mole of gaseous atoms
Which factors affect the first ionisation energy?
Nuclear charge, shielding, atomic radius, spin-pair repulsion
What shape are s-orbitals?
Spherical
What shape are p-orbitals?
Dumb - bell shaped
Why is the first ionisation energy always endothermic?
energy is required to break the attraction between the nucleus and outermost electron
What are the three types of subshell or orbital?
S - P - d
How many electrons can fit in a subshell or orbital?
2
How many electrons can fit in the first energy level or shell?
2
How many electrons can fit in the second energy level or shell?
8
How many electrons can fit in the third energy level or shell?
18
How many s-orbitals are there in each energy level?
1
How many p-orbitals are there in the second and third energy level?
3 - each
How many d-orbitals are there in the third energy level?
1
How is the spin of two electrons in an orbital related? Why?
Opposite, to minimise repulsion
Why do electrons fill orbitals singly first, before pairing up?
To minimise repulsion
What is a ‘delocalised’ electron?
An electron that can move
What is a lattice?
regular, repeating, 3D structure
Define ‘metallic bonding’
the electrostatic attraction between positive ions and delocalised electrons
Why are metals good conductors of heat?
their delocalised electrons move around and pass on energy whenever they collide with another electron or positive ion in the lattice
Why are metals good conductors of electricity?
delocalised electrons can move and carry charge through the structure
Why do metals have high melting points?
the electrostatic attraction between positive ions and delocalised electrons is strong
Why are metals malleable and ductile?
the electrostatic attraction between positive ions and delocalised electrons hold the layers together, but the regularity of the layers means they can slide over each other
What does ‘malleable’ mean?
can be hammered into shape
What does ‘ductile’ mean?
can be stretched into wires
Where do we find the atomic number of an element?
periodic table - bottom number
Where do we find the relative atomic mass of an element?
periodic table - top number
How do we calculate the relative formula mass of a substance?
add together the mass of all atoms present
What is a mole?
23
6.02 x 10 particles
What is a mole?
23
6.02 x 10 particles
What is the equation for converting between mass and moles?
moles = mass / Mr
What does the atomic number tell us?
the number of protons in the nucleus
How do we know how many electrons an atom has?
atoms have the same number of protons and electrons
How do we know how many neutrons an atom has?
subtract the atomic number from the mass number
What is a eukaryotic cell?
a cell with a nucleus and other membrane-bound organelles
What is the role of the nucleus?
Contains the nucleolus and chromatin
What is chromatin?
The genetic material
What is the role of the nucleolus?
Production of ribosomes
What type of ribosome is found in eukaryotic cells?
80s
Where are most ribsomes in a eukaryotic cell found?
On the surface of the rough endoplasmic reticulum
what is the function of ribsomes?
protein synthesis
what is the function of the rough endoplasmic reticulum?
modifies the proteins made by the ribsomes on its surface
what is the stucture of the rough endoplasmic reticulum?
a system of flattened sacs continuous with the nuclear membrane. the surface is covered with ribosomes
what do the mitochondria and nucleus have in common?
They have a double membrane
what is the stucture of the smooth endoplasmic reticulum?
a system of flattened sacs continuous with the nuclear membrane, there are no ribosomes on the surface
what is the function of the smooth endoplasmic reticulum?
produces and processes lipids, carbohydrates, and steroids
what is the function of the Golgi apparatus?
modifies proteins and lipids before packaging them into Golgi vesicles
what is the structure of the Golgi apparatus?
flattened membrane-bound sacs
what is the function of the Golgi vesicles?
transport and store biochemical molecules within a cell
what is the structure of the Golgi vesicles?
spherical membrane-bound sac
what is the structure of a lysosome?
spherical membrane-bound sac
what is the function of a lysosome?
contains lysozymes that are used to break down unwanted substances within the cell
what is the structure of a mitochondrion?
bound by a double membrane. the inner membrane is folded. contains mitochondrial DNA
what is the function of the mitochondria?
Aerobic respiration
what is the inner membrane of a mitochondrion called?
crista (plural cristae)
why are the cristae folded?
increase surface area to increase the rate of respiration
what is the structure of the cytoplasm?
gelatinous liquid
what is the function of the cytoplasm?
contains dissolved substances, site of anaerobic respiration & other cellular reactions
what is the structure of the plasma membrane?
it is made of a phospholipid bilayer with some glycolipids and proteins attached
what is the function of the plasma membrane?
to control what enters or leaves the cell and organelles
what is the structure of the centriole?
a barrel-shaped protein
what is the function of the centrioles?
control microtubules, which support the positioning and movement of the organelles; role in cell division
