Chemistry of Life Flashcards
What is an element?
The simplest form of matter with unique chemical properties
What is the atomic number of each element?
The number of protons in its nucleus
What is the periodic table?
The letter symbols of elements arranged by its atomic number
How many elements have a role in our body?
24
How much of our body weight consists of Oxygen, Carbon, Hydrogen, Nitrogen Calcium, and Phosphorus?
98.5%
How much oxygen (O) is in the body?
65%
How much carbon (C) is in the body?
18.5%
How much Hydrogen (H) is in the body?
9.5%
How much Nitrogen (N) is in the body?
3.2%
How much Calcium (Ca) is in the body?
1.5%
How much Phosphorus (P) is in the body?
1%
How much Potassium (K) is in the body?
0.4%
How much Sulfur (S) is in the body?
0.3%
How much Sodium (Na) is in the body?
0.2%
How much Chlorine (Cl) is in the body?
0.2%
How much Magnesium (Mg) is in the body?
0.1%
How many trace elements are in the body?
Less than 1%
Give examples of some elements that may have traces in the body
Boron (B), Chromium (Ce), Cobalt (Co), Copper (Cu), Fluorine (F), Iodine (I), Iron (Fe), Manganese (Mn), Molybdenum (Mo), Selenium (Se), Silicon (Si), Tin (Sn), Vanadium (V), and Zinc (Zn)
What is the nucleus?
The center an atom contains
What does the atomic number represent?
The number of protons
What is a proton?
The positive charge
What is a neutron?
The neutral charge
How do you determine the atomic mass?
It is the total number of protons plus the total number of neutrons
What is an isotope?
It is the same element based on the number of protons, but with a different number of neutrons
What is an electron?
The negative charge
How do you determine if an atom has a neutral charge?
If the number of electrons and protons are equal to each other
True or false: The electrons closer to the nucleus have higher energy
False. Electrons further from the nucleus have higher energy, interact with other atoms, and determine chemical behavior
How do you determine if an atom has a negative charge?
If the number of electrons is higher than the number of protons
How do you determine if an atom has a positive charge?
If the number of protons is higher than the number of electrons
What is the smallest quantity of an element that retains the unique properties of that element?
Atoms are the smallest particles defining an element
What is the smallest independently functioning unit of an organism?
A cell
Together, just four elements make up more than 95% of the body’s mass. These include what?
Oxygen, carbon, hydrogen, and nitrogen
On the periodic table of the elements, mercury (Hg) has an atomic number of 80 and a mass number of 200.59. It has seven stable isotopes. The most abundant of these probably have what?
More than 80 neutrons
What cannot be made in our bodies?
Elements
The difference between the mass number and the atomic number for an atom is that:
A) The mass number includes all the subatomic particles while the atomic number only includes neutrons
B) The atomic number includes all the subatomic particles while the mass number only includes neutrons
C) The mass number includes both protons and neutrons while the atomic number only includes protons
D) The mass number includes all the subatomic particles while the atomic number only includes protons
E) The atomic number includes both protons and neutrons while the mass number only includes protons
C) The mass number includes both protons and neutrons while the atomic number only includes protons
The atoms of the element calcium have an atomic number of 20. Which electron shell is its valence shell?
The fourth electron shell
The atomic number designates the number of what in the atom?
Protons. The number of protons in the atom is the atomic number.
Nitrogen has an atomic number of 7. How many electron shells does it likely have?
Two
Only one of these elements is not a common element in the human body. Which element is the one that is not abundant in our bodies?
A) Oxygen (O)
B) Hydrogen (H)
C) Carbon (C)
D) Iron (Fe)
E) Nitrogen (N)
D) Iron (Fe)
Although our bodies use iron in trace amounts, it does not make up a significant portion of our bodies.
Nitrogen atoms have an atomic number of 7. How many more electrons would a nitrogen atom need to complete its valence shell?
3
Which of these atoms is stable and unreactive?
A) Sodium (Na, atomic number 11)
B) Carbon (C, atomic number 6)
C) Argon, (Ar, atomic number 18)
D) Hydrogen (H, atomic number 1)
E) Phosphorus (P, atomic number 15)
C) Argon, (Ar, atomic number 18)
Its valence shell is full with 8 electrons so it is unreactive
H2O is an example of?
A) An isotope
B) An ion
C) A molecule
D) A molecule and a compound
D) A molecule and a compound
H2O is a molecule since it is more than one atom held together by bonds, and a compound since the atoms are not all the same element
A hydrogen bond, like those found between water molecules, will bond a hydrogen atom to what?
A) A slightly positive atom
B) An electronegative atom
C) A polar atom
D) A non-polar atom
B) An electronegative atom
Hydrogen bonding will occur between the two
Which of the following is a molecule, but not a compound?
A) H2O
B) 2H
C) H2
D) H+
C) H2
Consider an atom with 6 electrons in its valence shell. When that atom becomes an ion, it is most likely to:
A) Donate 6 electrons and become a cation
B) Accept 2 electrons and become a cation
C) Accept 2 electrons and become an anion
D) Donate 6 electrons and become an anion
E) Donate 2 electrons and become a cation
C) Accept 2 electrons and become an anion
Which of these compounds would be built from polar covalent bonds?
A) C3H8
B) C2H6
C) O2
D) C2H4O2
E) H2
D) C2H4O2
Although carbon and hydrogen share their electrons equally, once oxygen is added to the mix, the electrons can no longer be shared equally.
The prominent energy yielding nutrients are carbohydrates and what?
Lipids.
The prominent energy yielding nutrients are carbohydrates and what?
Lipids.
Adenosine Triphosphate (ATP) is an important molecule because it does what?
ATP stores energy for use by body cells
Which of the following statements about chemical bonds is true?
A) Covalent bonds are stronger than ionic bonds
B) Hydrogen bonds occur between two atoms of hydrogen
C) Bonding readily occurs between non-polar and polar molecules
D) Ionic bonds involve the transfer of neutrons a
Between atoms
A) Covalent bonds are stronger than ionic bonds
Which of these is a type of potential energy on our bodies?
A) Chemical energy
B) Radiant energy
C) Electrical energy
D) Mechanical energy
A) Chemical energy
Which of these types of chemical reactions requires an input of energy to occur?
A) Endergonic
B) Exergonic
C) Chemical
A) Endergonic
The prefix end- means inside/into, which is helpful to remember that energy has to be added into this reaction for it to occur
Which of these types of chemical reactions is a catabolic chemical reaction, but not an anabolic chemical reaction?
A) Exchange reaction
B) Decomposition reaction
C) Synthesis reaction
B) Decomposition reaction
You have been given Na+Cl- (sodium chloride) and K+I- (potassium iodide) salt compounds. You carry out a chemical reaction where your products are Na+I- (sodium iodide) and K+Cl- (potassium chloride). Which type of chemical reaction best describes the one you carried out?
A) Synthesis reaction
B) Decomposition reaction
C) Exchange reaction
C) Exchange reaction
In the following chemical equation, what is fructose?
Glucose + Fructose > Sucrose + Water
A reactant
A hydrogen bond, like those found between water molecules, will bond a hydrogen atom to what kind of atom?
An electronegative atom, and hydrogen bonding will occur between the two.
True or false: Elements can be made in our bodies
False, elements cannot be made in our bodies
You make lemonade by mixing water, lemon juice, and sugar together. The sugar is what?
A) A solute
B) A solution
C) A solvent
A solute. Solutes are chemicals that dissolve in the solvent, or water.
Salts are important to the human body because when they dissolve, they what?
They dissolve into ions other than OH- and H+. The human body needs these additional ions.
If the blood pH drops to 7.30, a buffer will have to act as a what?
A weak base. Acting as a weak base will bind excess hydrogen ions.
What type of compound is CH4 (Methane)?
An organic compound
When dehydration synthesis reactions occur, only one type of biological molecules forms peptide bonds. Which one?
A) Protein
B) Carbohydrates
C) Lipids
D) Nucleic acid
A) Protein
What is a difference between a saturated fatty acid and an unsaturated fatty acid is that a saturated fatty acid?
The saturated fatty acid has more hydrogen atoms bonded to it
Which of these is the largest carbohydrate molecule listed?
A) Sucrose
B) Glucose
C) Glycogen
C) Glycogen
Carbon atoms are particularly well suited for building our biological molecules because why?
A) They can make 4 covalent bonds
B) They can bond together to create a carbon skeleton
C) They make covalent bonds with atoms from many other elements
D) All of the above
D) All of the above
What does uracil do?
A) Contains nitrogen
B) Is a pyrimidine
C) Is found in RNA
D) All of the above
D) All of the above
Hydrophilic molecules do what?
They tend to have a lot of polar covalent bonds.
Which of the following molecules are an organic molecule?
A) NaCl
B) H2O
C) CH3
D) CaCl
C) CH3.
This is an organic molecule since it contains carbon.
Jenny mixes up a batch of pancake batter, then stirs in some chocolate chips. As she is waiting for the first few pancakes to cook, she notices the chocolate chips sinking to the bottom of the clear glass mixing bowl. The chocolate chip batter is an example of a what?
A) Solvent
B) Solute
C) Solution
D) Suspension
D) Suspension
Ty is three years old and as a result of a “stomach bug” has been vomiting for about 24 hours.
His blood pH is 7.48. What does this mean?
A) Ty’s blood is slightly acidic
B) Ty’s blood is slightly alkaline
C) Ty’s blood is highly acidic
D) Ty’s blood is within the normal range
B) Ty’s blood is slightly alkaline
The prominent energy yielding nutrients are carbohydrates and what?
Lipids
What is the metabolism?
It is the sum of all of the body’s chemical reactions
What is anabolism?
It is the assembly of more complex molecules from simpler molecules
What is catabolism?
It is the breaking down of more complex molecules into simpler molecules
How many elements have a role in our body?
Only 24
What are the three major monosaccharides?
Glucose, galactose, and fructose
What are disaccharides?
Pairs of monosaccharides
What are the three major disaccharides?
Sucrose, lactose, and maltose
What pairs of monosaccharides are in the disaccharide sucrose?
Glucose and fructose
What pairs of monosaccharides are in the disaccharide lactose?
Glucose and galactose
What pairs of monosaccharides are in the disaccharide maltose?
Glucose and glucose
What are examples of polysaccharides?
Starch, cellulose, and glycogen
What are the five primary types of lipids?
Fatty acids, triglycerides, phospholipids, eicosanoids, and steroids
What is the function of fatty acids?
They are a source of energy
What is the function of a triglyceride?
It is energy storage, thermal insulation, and binds and cushions organs
What is the function of a phospholipid?
Cell membranes, aid fat digestion
What is the function of an eicosanoid?
It is a chemical messenger
What is the function of a fat soluble vitamin?
Blood clotting, wound healing, and vision
What is the function of cholesterol?
Cell membranes
What is the function of a steroid hormone?
Chemical messenger
What is the function of bile acids?
They are steroids that aid in fat digestion
What does ATP contain?
Adenine, ribose, 3 phosphate groups. It is the universal energy carrying molecule
What does deoxyribonucleic acid (DNA) contain?
It contains the genetic code for cell division, sexual reproduction, the instructions for protein synthesis
What does ribonucleic acid (RNA) do?
It synthesizes the proteins coded for by DNA.
How long is DNA?
100 million to 1 billion nucleotides long.
How long is RNA?
3 forms of RNA range from 70 to 10,000 nucleotides long
What is acid?
It is a compound that releases hydrogen ions (H+) in solution
What is activation energy?
The amount of energy greater than the energy contained in the reactants, which must be overcome for a reaction to proceed
What is adenosine triphosphate (ATP)?
Nucleotides containing ribose and an adenine base that is essential in energy transfer
What is an amino acid?
It is the building blocks of proteins and are characterized by an amino and carboxyl functional groups and a variable side chain.
What is an anion?
It is an atom with a negative charge
What is an atom?
It is the smallest unit of an element that retains the unique properties of that element
What is the atomic number?
It is the number of protons in the nucleus of an atom
What is a base?
It is a compound that accepts hydrogen ions (H+) in solution
What is a bond?
It is an electrical force linking atoms
What is a buffer?
It is a solution containing a weak acid or a weak base that opposes wide fluctuations in the pH of body fluids
What is a carbohydrate?
It is a class of organic compounds built from sugars, molecules containing carbon, hydrogen, and oxygen in a 1-2-1 ratio
What do ions do?
They carry a charge, unequal numbers of protons and electrons
What is ionization?
The transfer of electrons from one atom to another
What is an anion?
It is an atom that gained an electron and has a net negative charge
What is a cation?
It is an atom that list an electron with a net positive charge
Where are electrolytes found?
They are found in blood plasma and throughout the body
What are the body’s most abundant electrolytes?
Na+, Ca2+, Mg2+, Cl-, PO43-, and HCO-3
What is a free radical ion?
A particle with an odd number of electron
A superoxide anion O2- is an oxygen molecule with an extra molecule, for example
