chemical component of cells, dna replication and translation, rna stuff (BMS EXAM 1)

mostly in laymans terms

What is the smallest particle of an element that retains its distinctive chemical properties

An atom, which consists of a positively charged nucleus surrounded by a cloud of negatively charged electrons

what 4 elements make up about 96% of a cells mass

carbon, hydrogen, nitrogen, oxygen

the number of ??? in an atoms nucleus determines its atomic number

protons

how is the mass of an atom calculated

number of protons + neutrons in the nucleus of the atom

why is a complete atom electrically neutral

because the number of protons and electrons are equal

an atom is most stable when its outermost ??? is completely filled

electron shell

what is a covalent bond

bond formed when 2 outer shell electrons are shared between two atoms that are locked in (next to each other)

2+ atoms held together by covalent bonds is a ???

molecule

how does polar covalent bond differ from nonpolar covalent bond

• polar covalent bond is a covalent bond where the sharing is unequal

• causes one atom to pull their shared electron more to its side, becoming more negative >:(

• and in turn the losing atom to become more positive <:D

• result is a magnet with a positive end and a negative end.

Non polar covalent is when the sharing is equal so both atoms remain unelectrified(neutral) :I

• non polar = no problems bcuz they share

• polar = problems, unequal

the nucleus of the atom is

dense and positively charged because its packed with protons

explain causes an atom to be “stronger”, pull electrons closer?

• elements with a bigger atomic number have more protons.

• The more protons you have, the stronger the attraction between the positive nucleus of the atom and the negative electron cloud of the shell, making this atom exert more force

explain electronegativity rq

• its the atoms tendency to attract electrons, aka how strong an atom is an element can be

• fun fact, oxygen and nitrogen are stronger and hydrogen and carbon are weaker

• therefore O and N develop partial negative charges while H and C get partial positive charges because they’re losers

what typa bond forms when an electron jumps ship from one atom to another

ionic bond

explain ionic bonds rq

• all atoms want a full shell. atoms interact bc they want to be stable, have a full outer shell

• when 2 atoms with a big difference in strength(electronegativity) meet, they transfer electrons instead of sharing them

• stronger atom takes as many electrons from the weaker as it needs to be stable

• stronger atom now has extra electrons, making it negatively charged, and the weaker one now has less electrons than protons making it positively charged

• stronger atom is now an anion (aniiiii- no- negative)

• weaker atom is now a cation

• their opposing charges make them form ionic bond

whats the chemistry word for an overpowered atom

a highly electronegative atom

what happens if a very electronegative atom leave behind a few electrons on the lesser electronegative one after their relations?

the less electronegative one is now gonna find another partner to get rid of these electrons or share them with someone who had more because it simply must be stable

which bond is stronger in humans and why, covalent or ionic

covalent because cellular environment is juicy (its mostly water)

explain hydrogen bond

• the actual atoms of oxygen and hydrogen have a power imbalance, so they have a polar covalent bond (unequal sharing)

• this causes O to be slightly negative and 2H to be slightly positive

• the resulting molecule H2O binds to other H2O molecules because of the magnetic attraction- O to H and H to O >:)

• since the bond is only based on the attraction (electrostatic btw) and not on sharing electrons or anything, its VERY WEAK

why hydrogen bond so weak compared to ionic bond and what’s the kicker

bcz hydrogen bonds are based on PARTIAL CHARGES, ionic bonds are based on FULLY CHARGED IONS

• The kicker: since the cells are juicy the hydrogen bond is weaker in the body. ionic bonds are only stronger in a vacuum

hydrogen bonds can include hydrogen, oxygen and ???

nitrogen, because nitrogen is the only other abundant element in the cells that is so very electronegative like oxygen

hydrophilic substances requirements?

• can form hydrogen bonds

• must have polar bonds

• mixes well with water

hydrophobic is what

• uncharged substance

• makes little to no hydrogen bonds

• no mix with water

explain hydrophobic force

pushing of nonpolar surfaces out of the hydrogen bonded water network which helps them get together. phospholipid bilayer basically

acid

a molecule what releases a proton when it dissolves in water, which lowers the pH

base

molecule that accepts a proton when dissolved in water, raising the pH

what are the monomers and their polymers

nucleotide - nucleic acid

amino acid - protein

sugars - carbohydrate/polysaccharide

fatty acid - lipid

explain condensation reaction

builds polymers by forming a sharing bond(covalent) bond, releasing a water molecule in the process

hydrolysis

separates polymers by breaking the covalent bond with the addition of a water molecule

primary role of sugars in cells

• main source of chemical energy for the cell (glucose)

• when glucose is broken down cell gets energy

• can form carbs (polysaccharides) for energy storage or structural support

• polysaccharide is a chain of sugars so when the cell needs energy it breaks some off

2 distinct regions of a fatty acid molecule

• the head (carboxyl group) charged and hydrophilic

• the tail (hydrocarbon chain) not charged and hydrophobic

molecules that have both hydrophobic and hydrophilic regions are called

amphipathic

whats the main function of fatty acids/lipids

forming lipid bilayers for structure in the cell

whats the basic amino acid structure

central carbon attached to amino group, carboxyl group, and side chain (r group)

bond formed between two amino acids

peptide bond

3 parts of a nucelotide

a 5 carbon sugar, nitrogenous base, and phosphate group

pyrimidines

cytosine, thymine, uracil- the small ones

purines

adenine and guanine, the big ones

ATP primary function

energy

central dogma

DNA → RNA → protein. transcription then translation

gene expression

when the information in a dna sequence turns into something useful, like protein or RNA

2 main differences between DNA & RNA

• RNA uses ribose(H) while DNA uses deoxyribose(OH)

• RNA uses uracil instead of thymine

mRNA

RNA that has instructions for making proteins

ribosomal RNA function