Chapter 2 - Chemistry of Life Flashcards
At the cellular level, ________ merges with life.
Life is ________.
chemistry
physical substance that takes up space and has mass
matter
What are the basic states of matter?
solid, liquid, gas, and plasma
How do the states of matter differ?
how much space the matter takes up, its volume or density
pure form of matter containing only one kind of atom
element
smallest particle of an element
atom
Earth is made up of < ____ elements, plus some others
100
What subatomic particles has a positive charge, has mass, and used to determine identity of a particular atom?
protons
What subatomic particles has a negative charge, has mass, and the number can change?
neutrons
Protons and neutrons make up the _______ of an atom
nucleus
What subatomic particles has a negative charge, mass is negligible, and the number can change?
electrons
What are extremely small, mostly “empty” space?
atoms, nucleus contains the mass
List the elemental composition within humans.
mnemonic.
CHNOPS: Carbon Hydrogen Nitrogen Oxygen Phosphorus Sulfur
How many elements in the periodic table are important to life?
25
What does the atomic number mean in the periodic table?
number of protons
What does the atomic mass mean in the periodic table?
number of protons AND neutrons
atoms of a particular element all have same number of protons, but they can differ in the number of neutrons
isotopes
different forms of an atom are called ________
isotopes
what is an example of an isotope?
carbon, carbon-14 has a half-life of 5700 years.
carbon dating
How many electrons are in an atom?
same number as protons in general
where are electrons located?
they orbit around the nucleus - “shells”
how many electrons can the inner shell hold?
2 electrons
how many electrons can the outer shell hold?
up to 8 each
name for electrons in the outermost shell
valence electron
chemical formula for water
H2O
chemical formula for oxygen gas
O2
chemical formula for glucose
C₆H₁₂O₆
Draw nitrogen (Atomic number = 7)
7 protons, 7 neutrons
7 electrons. 2 in inner shell and 5 outer (valence) shell
_______ between atoms are a form of chemical energy
Bonds
Why do atoms form bonds?
doing so moves them to a more stable energy state
How do atoms become more stable?
atoms have a propensity to attain complete shells
What are the 3 types of bonds?
covalent
ionic
hydrogen
sharing of electrons between atoms
covalent bonds
Example of covalent bond:
O2 or H2O
an atom of Oxygen is almost always bound to some other atom(s)
a group of atoms held together by covalent bonds.
They may be the same element or different elements
molecule
a ________ contains different elements
compound
what is the Law of conservation of mass?
matter is neither created nor destroyed in chemical reactions
transfer of electrons between atoms
ionic bonds
what is a charged atom called?
ion
_________ charged ions attract
Oppositely
Example of ionic bond
Sodium Chloride NaCl
Ionic Attraction
bonds between already covalently bonded hydrogen and an electronegative atom.
Polarity
hydrogen bonds
what is a polar molecule?
different areas of the molecule have slightly different charges
example of a polar molecule
water
List 1 polar and nonpolar compound
Water: polar
Methane: nonpolar - only sees positive all the way around
hydrogen bonding among water molecules
hydrogen bonds
what does hydrophilic mean?
“water loving”
hydro = water
philic = loving
Examples of hydrophilic compounds - compounds that readily interact with water
sugar, salt,
sodium chloride dissolves in water
Example of hydrophobic (“water hating”) compounds - compounds that form itself around water
oil, lipids
List the bond strengths from strongest to weakest
Covalent - strongest
Ionic - strong
Hydrogen - weak
List the unique properties of water
• Solvent – polarity allows water to interact with many substances
mediums for organisms
• Cohesive - because of many hydrogen bonds
• High heat capacity – lot of energy to force a temperature change
• High heat of evaporation - lot of heat to force a state change
Water molecules can ________ to produce ions
dissassociate
Acids and Bases
Acids yield:
H+ (hydrogen ions)
Acids and Bases
Bases accept:
H+
The amount of hydrogens in water determines its ________
acidity
Example of an acid
Hydrogen Chloride (HCl) - disassociates in water
Example of a base
Sodium hydroxide (NaOH) - disassociates i nwater
Hydroxide ions released react with hydrogen ions in solution to produce water, thus resulting in what?
decreasing the concentration of hydrogen ions
the concentration of hydrogen ions (H+) in a solution
pH
often referred to as ‘acidity’ of a solution
Scales from 0-14. 0 = most acidic, 14 = most basic.
Based on a log10 scale
Which of these solutions has a higher concentration of H+ ions?
pH 0.0001
pH 10-5
ph 0.0001 because it equals to 10-4
the change of 1 value is a difference of 10 fold
log scale
substances that keep pH from changing
buffers
most biological systems function within a narrow range of pH with the exceptions of which systems?
stomach and vagina - highy acidic
Buffers yield or accept H+, keeping pH in a narrow range.
true
Example of a buffer
carbonic acid-bicarbonate system.
it maintains the pH of blood at 7.4 (near neutral)
List the 4 biological molecules
carbohydrates
lipids
proteins
nucleic acids
framework of biological molecules “backbone element”
carbon
forms up to 4 covalent bonds
sugars and starches used as energy sources
carbohydrates
what are the 2 types of carbohydrates?
simple carbs
complex carbs
What is a simple carbohydrate with one sugar and give an example
monosaccharides
ex: glucose or fructose
What is a simple carbohydrate with two sugars and give an example
disaccharides
ex: lactose
what is a complex carbohydrate with many sugars and give an example
polysaccharides
ex: starch
what are complex carbohydrates
made of repeating units of simple sugars
many macromolecules (like complex carbs) are made of repeating units generally called ________.
monomers
what are monomers formed through?
dehydration synthesis - the removing of water
creating macromolecules by breaking apart complex carbohydrates through ________
hydrolysis
what is hydrolysis?
hydro = water
lysis = splitting
“water splitting”
molecules that facilitate biological functions
proteins
list the different types of proteins and their function
- Enzymes – Quicken chemical reactions
- Transport – Move other molecules
- Contractile – Muscles movement
- Structural – Physical or mechanical support
- Protective – defend against invaders and cancer
- Communication – cell to cell signaling
Proteins are ________.
Proteins are made up of _________ (repeating units)
polymers; monomers
= amino acids
made of relatively small chains of these amino acids
peptides
made of chains of peptides, thus longer chains of amino acids
proteins
building blocks of peptides and proteins
amino acids
how many types of amino acids are there and how do they vary?
20, vary in their ‘side chain’ (R)
what are essential amino acids?
only obtainable by humans from food
what are non=essential amino acids?
synthesized in body
List the protein structure
- Primary – specific sequence of amino acids
- Secondary – bending and coiling of the amino acid chain
- Tertiary – three-dimensional folding, that produces the shape of proteins
- Quaternary – some proteins have multiple polypeptide chains that interact
proteins that speed up chemical reactions, important type of protein
enzymes
________ are very specific, often only a single action
enzymes
Examples of enzymes?
Lactose
Lactase - breaks down lactose and produces glucose and galactose
What are lipids?
fats, oils, waxes.
insoluble in water - nonpolar
what is the ratio of H in lipids?
high ratio to O, 2:1
what are the major uses of lipids?
o Energy & energy storage
o Insulation
o Protection
o Cellular structure and function
What is insulation?
a poor conductor of heat, maintains heat internally (walrus and homeostasis)
What is a carboxl functional group
fatty acids
what is “saturated with hydrogens”
saturated fatty acids - no double bonds between carbons
double bonds between carbons change physical shape of the molecule, thus its behavior functions differently
unsaturated fatty acids
most common fat consumed in food
triglycerides
what is a triglyceride?
‘Tri’ = three fatty acids, bound to glycerol (an alcohol)
Describe a phospholipid:
- Hydrophilic head – readily interact with water
- Hydrophobic tails
- Phospholipid bilayer
fluid outside of the cell
extracellular fluids
what are two functions nucleotides are important for?
- Energy transfer in cells
2. Store and transmission of genetic information
breaking and forming of bonds in ATP = release and storage of energy
Cellular Energy Transfer
adenosine triphosphate
ATP - ‘energy molecule of cells’
the gasoline of the cell
adenosine diphosphate
ADP
DNA made of nucleotides, what are its “bases”:
Adenine
Guanine
Cytosine
Thymine
Where we see Adenine, we see ________ on the other side (hydrogen bonds)
Thymine
Where we see Guanine, we see ________, bounded by three hydrogen containing bonds.
Cytosine
sequences of bases ________ sequence of amino acids in proteins
determines
DNA/RNA nucleic acids
Deoxyribonucleic-acid long polymer made up of sequences of nucleotides
Pasteur refuted that people believed spontaneous generation of life is from the coming together of chemicals, but he found..
theres microscopic organisms in the air and tested with a glass trapping them.
CHNOPS is true, but there are 25 elements used by life. List some others.
Magnesium Potassium Manganese Iron Fluorine Sodium Chlorine Calcium Chromium Iron Copper Zinc
Difference between saturated and unsaturated fat?
Saturated fats don’t contain double bonded carbons, they are saturated with hydrogens
Difference between nucleotides and amino acids?
Nucleotides are a small molecule important for:
- energy transfer in cells and
- store and transmission of genetic information
Amino acids are monomers (repeating units) that make up proteins
proteins are made up of monomers (repeating units) called:
amino acids
