(Exam 1) What are atoms and elements?
____________ is much stronger for water than for most other liquids.
Cohesion
What are compounds?
Combinations of 2 or more elements.
Which type of macromolecule is an informational molecule?
DNA
Which of the following statements about chemical bonds is NOT true?
Methane (CH4) is the result of an ionic bond between two oppositely charged atoms of carbon and hydrogen.
What are astrobiologists?
Scientists who search for life elsewhere in the universe.
What Act currently dictates what information is presented in food labels?
The Nutrition Labeling and Education Act
What is a calorie?
a unit used to measure energy
Which of the following nucleotide bases are present in equal amounts in DNA?
adenine and thymine
Which of the following lists show all of the energy-containing nutrients used to estimate the total caloric value of food?
alcohol, fat, protein, carbohydrate
Phenylketonuria is an inherited disorder. Affected individuals have a defective enzyme called phenylalanine hydroxylase. The substance these individuals cannot break down is a(n)
amino acid.
On food packages, "insoluble fiber" refers to plant material that we cannot fully digest but is important for maintaining a healthy digestive tract. This substance refers to a(n)
carbohydrate
Glycoproteins are membrane proteins with bound
carbohydrates
Which of the following is a polysaccharide?
cellulose, the primary component of plant cell walls
Evaporation from the leaves of a tree will pull water up through the roots as an unbroken column throughout the entire height of the tree. This feat is possible because of which characteristic of water?
cohesion
Three principal types of bonds hold multiple atoms together. These are
covalent bonds, ionic bonds, and hydrogen bonds.
Chemical reactions cannot create or ____________ matter; they can only rearrange it.
destroy
Sucrose (table sugar) and lactose (the sugar found in milk) are examples of
disaccharides.
A covalent bond forms when 2 atoms share one or more pairs of ____________.
electrons
An atom can be changed into an ion by adding or removing _________.
electrons
A Calorie is the amount of ________ needed to raise the temperature of 1 kilogram of water 1 degree Celsius.
energy
Lactose is a combination of
glucose and galactose.
Which of the following are all monosaccharides?
glucose, fructose, and galactose
The fact that water is less dense as a solid than as a liquid explains why
ice floats on top of liquid water.
One important difference between covalent and ionic bonds is that
in covalent bonds two atoms share electrons, whereas in ionic bonds one atom gives one or more electrons to the other atom.
A nucleotide consists of a phosphate group, a pentose sugar, and a __________________, all linked together by covalent bonds.
nitrogen-containing base
DNA is made of
nucleotides.
When most liquids get cold, their molecules move closer together. Water is the _________, when water molecules get cold enough, they move apart with each molecule staying at arm's length from its neighbors forming ice.
opposite
In the Atwater system, what is the average value used for protein?
4 Kcal/g
One kcal is equal to ____ kilojoules.
4.184
A label for a bag of chips that contains 0 g protein, 33 g carbohydrates, and 30 g fat would have a total calorie count of:
402
Oxygen, carbon, hydrogen, and nitrogen make up ____% of the weight of the human body.
96%
What is the smallest unit of matter that still retains the properties of an element?
An atom!
A _______ molecule is one with an uneven distribution of charge that creates two poles, one positive pole and one negative pole.
polar
Hydrogen bonds have a _______ molecule.
polar
Relative to protons, electrons have
significantly less mass.
covalent bonds are the strongest or weakest?
strongest
What are protons, electrons, and neutrons called?
subatomic particles
Fiber is usually ______ from the total carbohydrate before calculating the calories.
subrtacted
A solution's acidity is a measure of
the H+ (free-floating protons) it contains.
In the original method used to determine kcals from food:
the food was completely burned
In DNA, adenine from one strand binds to ______ in the complementary strand.
thymine
"Real Science" doesn't follow the scientific method
true
____________ depend on cohesion to help transport water from their roots to their leaves.
Trees
How does floating ice help support life on earth?
When a deep body of water cools and a layer of ice forms on top, the floating ice acts as an insulating "blanket" over the liquid water, allowing life to persist under the frozen surface.
Originally, to determine the number of kcals in food ______________ was used.
a bomb calorimeter
An amino acid is to a polypeptide as
a nucleotide is to a nucleic acid
