Biochemistry, Water, Carbon
Carboxyl
1 Carbon double bonded to 1 oxygen and single bonded to a hydroxide
Methyl
1 Carbon, 3 hydrogens Nonpolar
Amino
1 Nitrogen, 2 Hydrogens
Hydroxyl
1 Oxygen, 1 Hydrogen Polar
Sulfhydryl
1 Sulfur, 1 Hydrogen
Carbonyl
1 carbon double bonded to 1 oxygen
Phosphate
1 phosphorus double bonded to one oxygen, single bonded to 3 Oxygens
How many orbitals does principal shell 1n have and how many electrons can it hold?
A single s subshell and it can hold a total of two electrons
How is the periodic table organized?
According to their atomic number. They are arranged in a series or rows and columns based on shared chemical and physical properties.
What is the other name of hydrocarbon chains?
Aliphatic hydrocarbons
Which biological processes follow the laws of physics and chemistry?
All of them
Where are functional groups founds?
Along the carbon backbone
Electrons contribute greatly to what?
An atom's charge
Electrons do not contribute much to what?
An element's overall atomic mass
Saturated fats usually come from where?
Animals
How do we use hydrocarbons in our daily lives?
As fuels
How can hydrocarbons exist?
As linear carbon chains, carbon rings, or combinations of both
What is an isotope?
Atoms that vary only in the number of neutrons they possess
Which of the following statements is true? A. Acids and bases cannot mix together. B. Acids and bases will neutralize each other. C. Acids, but not bases, can change the pH of a solution. D. Acids donate hydroxide ions (OH-); bases donate hydrogen ions (H+).
B
A molecule that binds up excess hydrogen ions in a solution is called an?
Base
Why can ions and polar molecules dissolve in water?
Because water is polar with slightly positive and slightly negative charge
cis configuration
Bent
How do buffers help prevent drastic swings in pH?
Buffers absorb the free hydrogen ions and hydroxide ions that result from chemical reactions. Because they can bond these ions, they prevent increases or decreases in pH.
How can organisms whose bodies require a near-neutral pH ingest acidic and basic substances and survive?
Buffers are the key. Buffers readily absorb excess H+ or OH- keeping the pH of the body carefully maintained in the narrow range required for survival.
How are energy levels in the Bohr model designated?
By a number and symbol n.
How are hydrocarbon chains formed?
By successive bonds between carbons that can be branched or unbranched
How is the geometry of the methane molecule determined?
By the shape of its electron orbitals
A molecule that binds up excess hydrogen ions in a solution is called a(n) ________. A. acid B. isotope C. base D. donator
C
Which of the following statements is false? A. Molecules with the formulas CH3CH2COOH and C3H6O2 could be structural isomers. B. Molecules must have a double bond to be cis-trans isomers. C.To be enantiomers, a molecule must have at least three different atoms or groups connected to a central carbon. D. To be enantiomers, a molecule must have at least four different atoms or groups connected to a central carbon.
C
What is the fundamental component for all macromolecules?
Carbon
What are the four elements common to all living organisms?
Carbon Hydrogen Nitrogen Oxygen
What property of carbon makes it essential for organic life?
Carbon is found in all living things because it can form up to four covalent bonds between atoms or molecules. These can be nonpolar or polar covalent bonds, and they allow for the formation of long chains of carbon molecules that combine to form proteins and DNA.
What property of carbon makeS it essential for organic life?
Carbon is unique and found in all living things because it can from up to four covalent bonds between atoms or molecules. These can be nonpolar or polar covalent bonds and they allow for the formation of long chains of carbon molecules that combine to form proteins and DNA.
As the backbone of living things, Hydrocarbons may exist as?
Carbon rings, linear chains of carbons or combination of both
What are the most abundant elements in living organisms?
Carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus
What kind of molecules are covalent bonds commonly found in?
Carbon-based organic molecules such as DNA and proteins
D forms enantiomers of amino acids are found where?
Cell wall of bacteria
What is a radioisotope?
Chemical elements whose nuclei are unstable and dissipate excess energy by emitting radiation in the form of alpha, beta, and gamma rays
Who devised the periodic table? When?
Dmitri Mendeleev in 1869
What is the shape of the p subshell's orbitals?
Dumbbells
What is a polar covalent bond?
Electrons that are unequally shared by the atoms and are attracted more to one nucleus than the other
T or F: Water is the most abundant molecule in the Earth's atmosphere.
False
When an electron is at its lowest level it is at what state?
Ground state
Which group on the periodic table have filled outer electron shells?
Group 18 Helium, Neon, and Argon
Which inorganic molecules utilize covalent bonds?
H2O, CO2, and O2
What type of bond represents a weak chemical bond?
Hydrogen
What is the one element that does not have any neutrons?
Hydrogen (made of one proton and one electron)
What within water molecules forms polar covalent bonds?
Hydrogen and oxygen
Why are hydrogen bonds and van der Waals interactions necessary for cells?
Hydrogen bonds and van der Waals interactions form weak associations between different molecules or within different regions of the same molecule. They provide the structure and shape necessary for proteins and DNA within cells so that they function properly.
Hydrogen bonds are responsible for what in regards to DNA?
Hydrogen bonds zip together the DNA double helix
How are functional groups usually classified?
Hydrophobic or hydrophilic depending on charge or polarity characteristics
Name the seven main functional groups.
Hydroxyl Methyl Carbonyl Carboxyl Amino Phosphate Sulfhydryl
What are the 7 functional groups?
Hydroxyl Methyl Carbonyl Carboxyl Amino Phosphate Sulfhydryl
Atoms fill which energy shell first?
the innermost shell
When carbons are on opposite side of a double bond, they are in _________ configuration.
trans
Fats with at least one double bond between carbon atoms are _________________ fats.
unsaturated
Fats with at least one double bond between carbon atoms are _________________ _________.
unsaturated fats
Trans configuration
usually linear
How are the carbons arranged in the trans configuration?
In a more or less linear structure
What makes ionic bonds different from covalent bonds?
Ionic bonds are created between ions. The electrons are not shared between the atoms, but rather associated more with one ion than the other. Ionic bonds are strong bonds but are weaker than covalent bonds, meaning it takes less energy to break an ionic bond compared with a covalent one.
Atoms that vary in the number of neutrons found in their nuclei are called _____________.
Isotopes
What happens to the carbon backbone in the cis configuration?
It bends
What is radioactive decay?
It describes the energy loss that occurs when an unstable atom's nucleus releases radiation
How many orbitals does principal shell 2n have and how many electrons can it hold?
It has one s and one p subshell and can hold a total of eight electrons
Triglycerides are liquid at room temperature. Why?
It is a cis unsaturated fat. The cis configuration creates a bend in a carbon backbone that does not allow the molecules to pack tightly so they remain liquid/oil at room temperature.
What is one of water's most important properties?
It is composed of polar molecules
The water's low density in its solid form is due to what?
It is due to the way hydrogen bonds are oriented as it freezes.
Name a good reason why N2 is good for living systems.
Its triple bond between nitrogens makes it hard for living systems to break apart so it can be used to make sustainable DNAs and proteins.
How are the hydrogen bonds of water broken?
Kinetic energy of the molecules due to the heat contained in the system
In nature, only which forms of amino acids enantiomers are used to make proteins?
L-forms
What do hydrocarbon chains consist of?
Linear chains of carbon atoms
Why are polar bonds often present in organic molecules?
Macromolecules often have atoms within them that differ in electronegativity.
What two subatomic particles have approximately the same mass? What is this mass in scientific notation?
Protons and neutrons 1.67x10^-24 grams or 1 amu
Compare and contrast saturated and unsaturated triglycerides.
Saturated triglycerides contain no double bonds between carbon atoms; they are usually solid at room temperature. Unsaturated triglycerides contain at least one double bond between carbon atoms and are usually liquid at room temperature.
How many orbitals does subshell f have?
Seven
A covalent bond is formed by what?
Sharing of a pair of electrons between two atoms
Which of the following is not a functional group that can bond with a carbon? A. Sodium B. Hydroxyl C. Phosphate D. Carbonyl
Sodium
Covalent bonds are ____________ and much more ____________ than ionic bonds.
Stronger Common
Which subshells have more complex shapes?
Subshells d an f
An element is a?
Substance that cannot be broken down by chemical reactions
How do you calculate the number of neutrons an element has?
Subtract the number of protons from the mass number
Where are functional groups found?
The carbon backbone of macromolecules
The valence shell determines what?
The chemical reactivity of an atom
What does a pH test measure?
The concentration of hydrogen ions in a given solution
What happens when 2 atoms chemically bond to form a molecule?
The electrons come together as the atoms form a chemical bond.
Why do atoms not just pass through one another?
The electrons that surround all atoms are negatively charged and negative charges repel each other.
Functional groups play a role in what?
The formation of molecules
Hydrocarbons play an important role in what?
The formation of molecules like DNA, proteins, carbohydrates and lipids
What happens when water is boiled?
The higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas (steam or water vapor).
The number of neutrons in an atom is significant to what?
The mass of an atom
What is electron transfer?
The movement of electrons from one element to another
What are the two regions of an atom?
The nucleus and the outermost region that holds its electrons
What is the difference in chemical reactivity between elements based on?
The number and spatial distribution of an atom's electrons
In uncharged, neutral atoms, what is true about the electrons and the protons?
The number of electrons orbiting the nucleus is equal to the number of protons inside the nucleus.
The valence shell is?
The outermost shell
Which electron shell has the highest potential energy?
The outermost shell
Hydrogen is ____________ facing a different direction than oxygen.
always
What does the Bohr model depict?
an atom's electron shell configuration
What is the octet rule?
atoms are more stable energetically when they have eight electrons in their valence shell, the outermost electron shell
Amino acids and cholesterol incorporate the __________ ring.
benzene
What are some elements that have naturally occurring isotopes?
carbon, potassium, and uraniam
The Bohr model shows the atom as a ________ ____________.
central nucleus
When carbons or on the same side of a double bond, they are in the _____ configuration.
cis
Aromatic hydrocarbons consists of ___________ rings of carbon atoms.
closed
Aromatic hydrocarbons
closed rings of carbon atoms
When acids are added to a solution, the pH should ____________.
decrease
Structural isomers
differ in the placement of their covalent bonds
Each element has a characteristic number of what equal to its atomic number?
electrons
Each electron's negative charge is ___________ to the positive charge of a proton.
equal
How many orbitals does subshell d have?
five
Functional groups
group of atoms that occur within molecules and confer specific chemical properties to that molecule
Geometric isomers
have similar placements of their covalent bonds but differ in how these bonds are made to the surrounding atoms
Low levels of hydrogen ions result in ________ pH.
high
Acids give off ___________ ions.
hydrogen
______________ ________ between functional groups are important to the function of macromolecules and help them fold properly into an maintain appropriate shape for functioning.
hydrogen bonds
A polar substance that interacts readily with or dissolves in water is _____________.
hydrophilic
Substances that do not interact well with water are considered _________________.
hydrophobic
Bases give off ____________ ions.
hydroxide
Individual carbon atoms have an ____________ outermost electron shell.
incomplete
What are electrolytes?
ions necessary for nerve impulse conduction, muscle contractions and water balance
Triple bonds lead to a _____________ configuration.
linear
Triglycerides with trans double bounds have __________ fatty acids that _________ able to pack tightly at room temperature and form ________ _______.
linear are solid fats
Alipathic hydrocarbons
linear chains of carbon atoms
High concentrations of hydrogen ions yield a ______ pH number.
low
Isomers
molecules that share the same chemical formula but differ in the placement of atoms and/or chemical bonds
Enantiomers
molecules that share the same chemical structure and bonds but differ in the 3D placement of atoms so that they are mirror images of one another
How much of the volume of an atom is empty space?
most of it, greater than 99%
Which subatomic particle is variable, resulting in isotopes?
neutrons
What do the most abundant elements in living organisms help to form?
nucleic acids, proteins, carbohydrates, and lipids
The unique chemical properties of an element is defined by its?
number of protons
Double bonds lead to a _________ configuration.
planar
Water is what kind of molecule?
polar
Which subatomic particle determines an element's atomic number?
protons
There is a connection between the number of ____________ in an element, the ____________ ___________ that distinguishes one element from another and the number of __________ it has.
protons atomic number electrons
Atoms contain what three main subatomic particles?
protons, neutrons, electrons
Single bonds allow ______________ along the axis of the bond.
rotations
Name the subshells of principal shell 3n.
s, p, and d subshells that can hold 18 electrons
Name the subshells of principal shell 4n.
s, p, and d subshells that can hold 18 electrons
How are the subshells designated?
s, p, d, and f
Molecules with other elements in their carbon backbone like nitrogen or oxygen are _______________ _______________.
substituted hydrocarbons
What is an orbital?
the area where an electron is most likely to be found
What is atomic mass?
the calculated mean of the mass number for its naturally occurring isotopes
How many elements are there?
118
Which orbital is always filled first?
1s orbital
How many regions does an atom consist of?
2
The innermost shell has a maximum of ____ electrons.
2
An atom has 5 electrons in its outer shell. How many unpaired electrons does it have?
3
How many orbitals does the p subshell have?
3
How many covalent bonds can a carbon atom make?
4
If xenon has an atomic number of 54 and a mass number of 108, how many neutrons does it have?
54
What is pH inside cells?
6.8
What is the pH in the blood?
7.4
How many elements occur naturally?
92
When acids are added to a solution, the pH should ________. A. decrease B. increase C. stay the same D. cannot tell without testing
A
Which of the following is not a functional group that can bond with carbon? A. sodium B. hydroxyl C. phosphate D. carbonyl
A
What is an ionic bond?
A bond formed between ions with opposite charges
Electrons fill orbitals in what kind of order?
Consistent
What does the hybridization of orbitals mean?
Covalent bonds change the shape of orbitals.
Each carbon molecule can bond with as many as________ other atom(s) or molecule(s). A. one B. two C. six D. four
D
Which of the following statements is not true? A. Water is polar. B. Water stabilizes temperature. C. Water is essential for life. D. Water is the most abundant molecule in the Earth's atmosphere.
D
What do hydrogen bonds provide?
Many of the critical life-sustaining properties of water and also stabilize the structures of proteins and DNA
What is the simplest hydrocarbon molecule?
Methane
Which hydrocarbon is the simplest?
Methane (CH4)
What kind of charge does a water molecule have?
No net charge. The polarity of water creates a slightly positive charge on the hydrogen and a slightly negative charge on oxygen, contributing to water's properties of attraction.
The electrons in which energy level determine the energetic stability of the atom?
Outermost level
Which two atoms are most electronegative?
Oxygen and Nitrogen (They "hog" electrons)
How are water's slightly positive and slightly negative charges generated?
Oxygen is more electronegative than hydrogen, making it more likely that a shared electron would be found near the oxygen nucleus than the hydrogen nucleus, thus the partial negative charge is near the oxygen.
A _________ of electrons represent an orbital.
Pair
Rows are the same as what on the periodic table?
Periods
What happens when the temperature of water is reduced?
The water molecules form a crystalline structure maintained by hydrogen bonding (there is not enough energy to break the bonds) that makes ice less dense than liquid water.
What is a nonpolar covalent bond?
These bonds form between two atoms of the same element or between different elements that share electrons equally
How are functional groups classified?
They are either hydrophobic or hydrophilic depending on their charge or polarity characteristics
How are the 26 unnaturally occurring elements made?
They are synthesized in laboratories and are unstable
How do geometric isomers differ?
They have similar placements of their covalent bonds but differ in how these bonds are made to surrounding atoms, especially in carbon-to-carbon double bonds.
Where do non-neutral pH readings come from?
They result from dissolving acids or bases in water.
What happens if there are multiple orbitals of equal energy?
They will be filled with one electron in each energy level before a second electron is added
Which kind of covalent bond is the strongest?
Triple bond
True or false: Acids and bases will neutralize each other.
True
What is a molecule?
Two or more atoms chemically bonded together
For a van der Waals interaction to occur, molecules need to be where in relation to each other?
Very close to each other
The properties of what element are key to understanding living processes?
Water
Are hydrogen and van der Waals bonds weak or strong?
Weak
Can a hydrocarbon have both alipathic and aromatic portions?
Yes, an example is beta-carotene
