Chapter 2: Life Chemistry and Energy Flashcards Preview

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Flashcards in Chapter 2: Life Chemistry and Energy Deck (63):
1

atom

smallest unit of matter that defines chemical elements

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nucleus

Dense and positively charged

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electrons

negatively charged
negligible mass

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protons

positively charged
mass of 1

5

neutrons

no charge
mass of 1

6

element

oure substance
just one kind of atom

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True or false: like charges attract

false, they repel
opposite charges attract

8

dalton

unit of measure
mass of a proton

9

What are the six major elements in organisms?

Hydrogen (H)
Nitrogen (N)
Sulfur (S)
Phosphorous (P)
Carbon (C)
Oxygen (O)
CHNOPS

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atomic number

number of protons in an atom
unique to each element

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mass number

neutrons and protons

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Bohr Model

largely empty space
central nucleus
electrons orbit

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electron shells

electrons in orbit

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molecules

atoms bonded together

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octet rule

atoms like to form stable molecules so that have 8 elections in their outermost shells so they can be super happy

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chemical bond

attractive force that links two atoms together in a molecule

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Ionic bonds

form when atoms gain or lose one or more electrons to achieve stability

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covalent bonds

atoms share electrons
strong

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Hydrogen bonds

weaker
SUPER IMPORTANT IN BIO
#proteins #water #literallyeverythingever

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Functional Groups

groups of atoms that give important properties to biological molecules

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Ion

electrically charged particle that froms when an atom gains or loses one or more electrons

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Cations (CatIons)

positively charged ions
think Na+

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Anions (AnIons)

negatively charged ions
Think Cl-

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Ionic bonds

form as a result of the electrical attraction between ions bearing opposite charges

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Salts

products of ionic bonds

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Are ionic bonds typically strong in living systems?

Nope, they are typically weak (they are in solutions)
generally water
and salts dissolve in water

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Covalent Bond

two atoms attain stable electron numbers in their outermost shells by sharing one or more pairs of electrons

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single bond

sharing of a single pair of electrons

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double bond

involves the sharing of four electrons, two pairs

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Triple bonds

rare
six shared electrons
like the gold standard of bonds

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electronegativity

the attractive force that an atomic nucleus exerts on electrons in a covalent bond

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nonpolar covalent bonds

atoms have very similar electronegativities
share electrons equally

33

Polar covalent bond

unequal electron sharing
drawn to more electronegative nucleus

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hydrogen bond

Hydrogen + really electronegative molecule
weaker than covalent

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heat capacity

how much heat needs to be added for a temperature change

36

Heat of vaporization

the heat required to change from liquid to gaseous state

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Cohesion

capacity to resist coming apart when placed under tension

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Hydrophilic

water loving
polar

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Hydrophobic

water hating
nonpolar
hydrocarbon molecules

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Macromolecules

large molecules
formed by covalent linkages of smaller molecules

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polymers

most biological molecules constructed by the covalent bongin of smaller monomers (except lipids like to be different and do their own thing)

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Condensation

removal of water links monomers

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hydrolysis

water breaks polymer into monomers

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Carbohydrates

large group of molecules that all have similar atomic compositions but differ in sixe, chemical properties, and biological functions
general forumla Cn(H2O)n

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Important roles of Carbohydrates

source of stored energy that can be released in a form usable by organisms
used to transport stored energy
function as structural molecules
recognition or signaling molecules

46

Lipids

hydrocarbons
insoluble in water
nonpolar covalent

47

Important roles of lipids

store energy in C-C and C-H bonds
structural roles in cell membrane sand on body surfaces
thermal insulation

48

nucleotide

consists of three components: a nitrogen-containing base, a pentose sugar

49

DNA

deoxyribonucleic acid

50

RNA

ribonucleic acid

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Catalysts

substances that speed up reactions without themselves being permanently altered
increases rate of reaction
CAN NOT MAKE REACTIONS OCCUR

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enzymes

proteins
biological catalysts

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Transition state

reactive mode caused by an input of energy

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Activation energy

the energy required to make a reaction happen

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Active site

where molecules bind to

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Enzyme-substrate complex (ES)

binding of a substrate to the active site of an enzyme produces this

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competitive inhibitor

competes with substrate for the active site

58

noncompetitive inhibitor

binds to an enzyme at a site distinct from active site

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Allosteric Regulation

non-substrate molecule binds or modifies a site other than the active site of an enzyme

60

Anabolic Reactions

link simple molecules to form more complex
capture energy
endergonic
endothermic

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Catabolic Reactions

break down complex molecules into simple
release energy
exergonic
exothermic

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First law of thermodynamics

energy is neither created nor destroyed

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second law of thermodynamics

disorder tends to increase
chaos is a ladder