biochemistry Flashcards
What is the charge of protons?
positive
What are the three subatomic particles that make up an atom?
protons neutrons and electrons
What is the charge of neutrons?
neutral (no charge)
What is the charge of electrons?
negative
What does the atomic number of an element tell you?
The number of proteins in an atom of that element. the number of protons equals the number of electrons
What does atomic mass tell you?
the number of protons + neutrons in an atom of that element
What is an atom?
the smallest unit of matter
What is an element?
a pure substance made up of only ONE type of atom
What is a molecule?
two or more atoms covalently bonded together
What is a compound?
atoms of two or more different elements joined together
What is the difference between an ion and an isotope?
An atom that loses or gains electrons becomes an ion. An atom that have more or less neutrons than usual is an isotope
What is the difference between a covalent bond and an ionic bond?
Covalent bonds form when atoms share electrons in order to become stable
Ionic bonds form when electrons are transferred from one atom to another in order for the atoms to become stable and the resulting ions are attracted to each other because of their opposite charges
Why do atoms form bonds?
Atoms form bonds in order to become stable. They are stable when their outer electron level is full
What is a hydrogen bond?
A hydrogen bond is a weak attraction between H and O in different water molecules (and in a few other types of molecules)
What is the difference between cohesion and adhesion?
cohesion is an attraction to the same type of molecule. Adhesion is an attraction to something different
How do surface tension and capillary action help living things?
Surface tension allows small organisms to move across bodies of water.. Capillary action moves water up from the roots to tree to the rest of the plant
Why is it important for living things that water takes a long time to heat up or cool down?
Our bodies are mostly water so it helps our bodies not get too hot or too cold. helps us maintain HOMEOSTASIS
Why is it important for living things that ice floats?
it keeps lakes and ponds from completely freezing in winter so all the organisms that live in the water can survive
Why is water called a universal solvent?
water can dissolve many different substancces
WHere on the pH scale are acids found? What type of ions is most concentrated in acids?
Acids are less than 7 on the scale. H+ (hydrogen ions) are concentrated in acids
Where on the pH scale are bases found? What type of ion is most concentrated in bases?
Bases are more than 7 on the scale. OH- (hydroxide ions) are concentrated in bases
WHat is the pH of a substance that is neutral? Give an example of a neutral substance
Neutral is 7 on the pH scale. Water is a neutral substance
WHat four elements make up 96% of any living thing?
CARBON, HYDROGEN, OXYGEN, AND NITROGEN
How can you tell if a substance is organic or not?
Organic compounds contain carbon
What are the monomers of carbohydrates, proteins, and nucleic acids?
Carbs: monosaccharides, Proteins: amino acids, Nucleic acids: nucleotides
What are the functions of carbohydrates?
quick energy or store energy
What are the functions of lipids?
store energy, cell membranes, insulation, protection
What are the functions of proteins?
body structure, speed up reactions (enzymes),
WHat are the functions of nucleic acids?
store genetic information, help make proteins
Why do living organisms need enzymes?
so that reactions can go fast enough to sustain life
Enzymes speed up reactions by reducing the ______?
Activation energy of a reaction (Which is the energy needd to start the reaction)
The substance that an enzyme binds to is called the ____?
Substrate
The pocket on the surface of an enzyme where things can bind is called the _______?
active site
What happens to an enzyme after a reaction?
it is not changed. it is ready to work again if new substrate is added
What happens to an enzyme if you boil it or put it in acid?
The heat or acid makes the shape of the enzyme change so that is can’t function anymore. it denatures the enzyme
What is a polar molecule?
molecules that have slightly charged areas
the charge is due to the uneven distribution of electrons between atoms
WHy is a water molecule polar?
the oxygen atom with 8 protons in its nucleus has a stronger attraction for the shared electrons than the hydrogens with only 1 proton in each nucleus
therefore, the shared electrons will be closer to the oxygen
this gives the oxygen a slightly negative charge and the two hydrogen atoms a slightly positive charge
What is cohesion?
a force which attracts molecules of the same substance
the water molecules arrange themselves so that the positive end of one is next to the negative end of another molecule of water. these attractions are called hydrogen bonds
the attraction between the polar water molecules is responsible for what is called surface tension
What is adhesion?
attraction between two unlikely substances such as water and glass is called adhesion
when water sticks to a surface, it is because of the positive and negative forces between the two different substances involved
adhesion is responsible for capillary action, which is the force that draws water up roos to the rest of a plant
Why is water the universal solvent?
water dissolves many different substances (solids liquids, and gases)
one reason that water is able to dissolve many substances is that the charged ends of the water molecule attract the molecules of other polar substances
What is a mixture?
a mixture is a material composed of 2 or more elements or compounds that are physically mixed together but not chemically combined
What is a solution?
a mixture that forms when all the components are evenly distributed within each other
What is a solute?
a substance that is dissolved in a solution
What is a solvent?
a substance that does the dissolving in a solution
What does the pH scale measure?
pH scale measures the concentration of H+
IT ranges from 0-14
each step on the pH scale increases by a factor of 10
What is an acid?
acidic solutions contain higher concentrations of H+ ions than pure water
pH values are below 7
What is a base?
basic/alkaline solutions contain lower concentrations of H+ ions than pure water
pH values are above 7
What is an organic compound?
in biology, the word organic means “relating to organisms” NOT food grown without the use of pesticides, antibiotics, or other industrial chemicals
all organic compounds can also be synthesized (created) in the lab
Why is carbon ideal for making different compounds?
Carbon atoms have four valence (outer shell) electrons, allowing carbon to form covalent bonds with many elements including hydrogen, oxygen, phosphorus, sulfur, and nitrogen
carbon can also bond to other carbon atoms, which gives carbon the ability to from chains that are almost unlimited in length
it an form millions of different large and complex structures
What are macromolecules?
they are giant molecules that are made from many smaller molecules
What is polymerization?
how macromolecules are formed! smaller units (monomers) join together to form larger compounds (polymers)
What organic compounds are needed by all living things?
carbohydrates
nucleic acids
lipids
proteins
What are carbohydrates?
main source of energy for organisms
HOw is extra sugar stored?
extra sugar is stored as macromolecules called polysaccharides
WHat are the uses of polysaccharides?
animals store extra sugar as glycogen
plants store excess sugar as starch
plants store it as cellulose, a strong, rigid fiber used for support
WHat are lipids? (fats, oils, and waxes)
long-term energy storage, insulation, waterproof covering, part of cell membranes, chemical messengers (steroids)
How are lipids formed?
when a glycerol molecule combines with fatty acids
What are nucleic acids?
they store and transmit hereditary, or genetic information
What are proteins made up of?
nitrogen, carbon, hydrogen, ad oxygen (most also have sulfur)
What are the functions of proteins?
provide structural support in bones and muscles
form parts of cell membranes
function as hormones to regulate the body
form antibodies to protect against infection
increase the rate of chemical reactions
What is a polypeptide?
When the amino acids join they form a polymer called a polypeptide
How are proteins organized?
Primary: chain of amino acids
Secondary: when sequence of amino acids are linked by hydrogen bonds
Tertiary: occurs when attractions are present between alpha helices and pleated sheets
Quaternary: consisting of more than one amino acid chain
What are enzymes?
a type of catalyst, which works to speed up a chemical reaction
What are enzymes?
proteins that help molecules react with one another
What is a chemical reaction?
it is the process of changing one set of chemicals (reactants) into another set of chemicals (products) by rearranging the atoms
What is a catalyst?
it is a substance that speeds up the rate of a chemical reaction
WHat is activation energy?
it is the amount of energy needed to start a chemical reaction
What is a substrate?
enzymes bind to or break molecules called substrates
these substrates are the reactants that are catalyzed by the enzyme
What is the active site?
the site on the enzyme where the substrates bind
What is the Lock ad Key Hypothesis?
enzymes bind to the substrates based on thier complementary shape
the fit is so exact that the active site and substrate are compared to a lock and key
What does lactase do?
break down lactose into glucose and galactose
What does sucrase do?
breaks down sucrose (common table sugar) into glucose and fructose
WHat does amalyse do?
breaks down starch in your mouth and stomach
What does lipase do?
breaks down ats
What does Pepsin do?
breaks down proteins
How are enzymes affected by the reaction?
Enzymes are NOT Changed by the reactions they catalyze therefore they are reusable
How can enzymes be affected?
temperature and pH
Why are enzymes considered the body’s workers
nearly every reaction in your body is helped by an enzyme
