unit 2 Flashcards
what is matter?
anything that has mass and takes up space
what are atoms?
building blocks of matter
what are atoms are made up of?
protons, neutrons, and electrons
what are elements?
pure substances that cannot be broken down
what are the main 4 elements of living things?
hydrogen, oxygen, nitrogen, carbon
what are trace elements?
iodine, flourine, iron
what are compounds?
2 or more different elements combined
what is water?
compound formed by hydrogen and oxygen
what are chemical bonds?
force that holds substances together
how can atoms become more stable?
by losing or adding electrons from other atoms
what is a covalent bond?
share electrons (nonmetal and nonmetal)
what is a ionic bond?
transfer electrons (metal and nonmetal)
what are the ends of a water molecule?
hydrogen ends are positive and oxygen ends are negative
what is the distribution of electrons in water molecule?
unequal, results in oppositely charged regions
what is the hydrogen bond?
(hydrogen and lone pair)
how much water is in living things?
50-70%
how does water benefit chemical reactions?
makes reactions in your body possible
what is cohesion?
like molecules attract each other, ex: water molecules stick together to form ocean
what is adhesion?
different molecules attract each other, ex: tape sticks to paper
what is high surface tension?
water has it, strong “skin” allows things to float on it
what is a capillary action?
water moving up a thin tube by itself, ex: meniscus in a graduated cylinder bc water sticks to the glass
what is a meniscus?
curve at the surface of a liquid, especially in a graduated cylinder
why does ice float on liquid water?
its less dense, ice has more “ordered” hydrogen bonds
whats the greatest water density?
4 celsius
why is it important for ice to float?
animals are part of habitats that contain ice ex: polar bears, if ice freezes all life underwater will be gone
what is a solvent?
liquid that dissolves something, ex: water or something
what is a solute?
substance being dissolved, ex: salt
how is a solution created?
solvent + solute
what are hydration shells?
ionic compounds are surrounded by these clusters of water molecules, allow particles to spread out evenly in the water
what is a hydrophilic substance?
substance attracted to water
what is a hydrophobic substance?
substance not attracted to water
what is the pH of water?
7 bc its neither acidic or basic in its pure state, pH changes when substances are dissolved in it
describe high specific heat in water
takes a lot of energy to raise temperature of water, it can take in a lot of heat without it rising much
what is evaporative cooling?
evaporation helps cool air, liquid evaporates -> remaining surface cools
what does an adequate diet consist of?
fuels, raw materials, essential nutrients
what is fuel?
contains proteins, carbs, and fats the body can use to make ATP
what are raw materials?
used for biosynthesis, ex: chains of carbon molecules or amino acids
what are essential nutrients?
substances that the animal cannot make for itself, ex: vitamins
what are organic molecules?
molecules that contain carbon, ex: carbs and proteins
what are inorganic molecules?
minerals that don’t contain carbon, ex: calcium or iron
why does your body need water?
so it can get rid of wastes, keep temperature stable and protect your spinal cord and tissues
what are grains?
food group that provide vitamin E, ex: wheat and rice
what are vegetables?
food group that provide carbs, vitamins A, C, E, etc.
what are fruits?
food group that provide carbs, vitamins, A, C, E, etc.
what is dairy?
food group that provide protein, fats, carbs, etc.
what is protein?
food group that provide complete proteins, fats, etc.
how many calories are in one gram of fat?
9
how many calories are in one gram of carbs?
4
how many calories are in one gram of protein?
4
what are enzymes?
they are catalysts that speed up chemical reactions in the body
how does a chemical reaction start?
weak chemical bonds in reactant, get activation energy for molecules to absorb
how do enzymes affect activation energy?
they lower the amount required to start a chemical reaction
what is an active site?
where enzyme and substract molecules have a chemical reaction
are enzymes specific?
yes they usually only work with only 1 substrate, “lock and key”
explain the phrase “lock and key”
enzyme and substrate fit exactly into one another, have specific shapes
what happens to an enzyme at the end of a chemical reaction?
enzyme is unchanged and can be reused
what is denaturation?
changes shape of the enzyme
how can temperature affect an enzyme?
increases enzyme activity
how can a change in pH affect an enzyme?
leads to change in shape of active site
how does the body use enzymes during digestion?
turns nutrients into substances that the digestive tract can absorb, hydrolysis reaction
what is a hydrolysis reaction?
the breakdown of compounds with the presence of enzymes and its reaction with water
what is the monomer for carbohydrates?
monosaccharide
what is the monomer for proteins?
amino acids
what is the monomer for nucleic acids?
nucleotides
what is the polymer for carbohydrates?
polysaccharide
what is the polymer for proteins?
proteins
what is the polymer for nucleic acids?
nucleic acids
what are the elements contained in carbohydrates?
C, H, O
what are the elements contained in protein?
C, H, O, N
what are the elements contained in nucleic acids?
C, H, O, N, P
what are the elements contained in lipids?
C and H mostly, also has O
what is the function of carbohydrates?
source of energy
what is the functions of proteins?
energy, repair body and tissues
what is the function of proteins?
genetic info
what is the function of lipids?
energy storage, steroids, cell membrane
what are examples of carbohydrates?
glucose and starch
what are examples of proteins?
enzymes and muscle
what are examples of nucleic acids?
DNA and RNA
lipids example
oil and butter
what does it mean for water to be a universal solvent?
it means that it can dissolve many substances
