Cell compounds and biological molecules Flashcards

Terms Definitions
Amino group?
Carboxyl group?
Hydrophilic means water loving. Hydrophilic substances dissolve in water (things that are polar and ionic).
Nucleic acids?
Organic molecules composed of nucleotide molecules. They include DNA, RNA, and ATP.
Organic chemical compounds composed of Carbon, Hydrogen and Oxygen. In general they provide energy for organisms. They are made up of simple sugars.
Small organic subunits that join together to form larger molecules called polymers.
Atoms of the same element with different numbers of neutrons. (note: their proton number stays the same)
A simple sugar (monosaccharide) with a six sided ring structure. It provides plants and animals with energy.
Hydrogen bond?
The weak bond that occurs between water molecules due to the attraction of the positive hydrogen side of one water molecule to the negative oxygen side of another water molecule.
Values for acidic pH?
less than 7 to 0.
The monomer of nucleic acids. They are composed of a phosphate group, a sugar, and a nitrogenous base.
4 Nitrogenous bases in RNA?
Adenine (A)
Uracil (U)
Guanine (G)
Cytosine (C)
Quaternary structure?
More than one polypeptide chain stuck together to make a protein. These are help together by R group interactions.
Amino Acid?
Monomer that makes up proteins. They have 3 distinct parts: an amino group, an R group, and a carboxyl group.
4 nitrogenous bases in DNA?
Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)
Lipid molecule that makes up the cell membrane of cells and thus regulates the flow of substances in and out of the cell.
Exergonic reaction?
A reaction in which energy is released
Endergonic reaction?
A reaction in which energy is absorbed.
Monomer of fat that contains 3 carbon atoms in a chain.
Values for a basic pH?
greater than 7 to 14.
Covalent bond?
The bond that forms between atoms when electrons are shared equally. This happens between two non-metals.
Cohesion of water molecules?
Cohesion means water molecules stick to each other. Cohesion results from hydrogen bonds.
Polar covalent bond?
When elctrons are not shared equally in a covalent bond. As a result one side of the molecule becomes slightly negative and the other side becomes slightly positive. Water is an example of a polar covalent bond. The oxygen side is more negative than the hydrogen side.
Tertiary structure?
The final 3 dimensional shape of a protein. Tertiary structure is held in place by 4 types of bond: 1. Hydrogen bonds 2. Ionic bonds 3. disulphide bonds 4. Hydrophobic interactions.
Formula for Glucose and empirical formula?
Formula: C6H12O6
Empirical formula (simplest formula): CH2O
Function of ATP?
ATP = adenosine triphosphate.
It is an energy molecule in living organisms.
Saturated and Unsaturated fats?
Saturated fats: Contain fatty acid chains with no double bonds thus cannot accept more Hydrogen ions. These are animal fats and are solid and room temperature.
Unsaturated fats: Contain fatty acid chain WITH double bonds thus they are not fully saturated with hydrogen ions. These are plant fats and are liquid at room temperature.
Double covalent bond?
When two pairs of electrons are shared between atoms.
Structure of DNA?
Double helix. It is made of two strands (double) of nucleotides that are held together by hydrogen bonds between base pairs, and they are twisted in a helix shape.
What causes denaturation of proteins?
1. Wrong pH
2. High temperature
3. Wrong salinity (salt levels)
4. Heavy metals (lead, mercury)
Function of DNA?
Has the code for making all proteins in our cells. It is like a recipe book.
Composition of an atom?
Atoms are made of protons and neutrons found in the middle part of the atom and electrons that float around the outside in electron shells
Alpha and Beta glucose?
There are two forms (two isomers) of glucose, Alpha and beta. Chains of alpha glucose make up starch and chains of beta glucose make up cellulose.
What are the 4 structures of proteins?
Primary, secondary, tertiary and quaternary.
Where in cells are phospholipid molecules found?
In the phospholipid bilayer of the cell membrane.
What forms the two sides or back bones of the molecule?
Sugar and phosphate groups.
Functions of RNA?
1. Makes a copy of DNA and takes this copy to ribosomes where the protein is made (mRNA or messenger RNA)
2. t RNA or transfer RNA takes amino acids to the ribosomes so they can be joined together to make proteins.
3. rRNA (ribosomal RNA) make up part of the ribosomes.
Are phospholipids hydrophobic or hydrophillic?
The head is hydrophilic and the tail is hydrophobic.
Summary of the bonds that hold together primary, secondary, tertiary and quaternary structure in proteins?
Primary - peptide bonds
Secondary - hydrogen bonds
tertiary - hydrogen bonds, disulphide bonds, ionic bonds, and hydrophobic interactions.
Quaternary-R group interactions
How can radioactive isotopes be useful in biology?
They can be used as radioactive tracers to follow molecules as they undergo chemical change in the organism.
Why is adhesion important in living organisms?
Water molecules stick to the cell walls of plant's thin veins which helps prevent the water from falling backwards due to gravity.
What type of bond is found between amino acids in a protein?
Peptide bond formed through the process of dehydration synthesis.
How do we make pure water acidic?
By adding hydrogen ions (H+) to the water. For example, adding HCl to the water would increase the number of Hydrogen ions (H+), making the water more acidic.
Where is the energy in ATP?
ATP stores energy in the bonds of the phophate groups.
What are some examples of how the "moderating" effect of water is important to living things?
1. Water helps to cool animals when they perspire. Perspiration cools the animal because when the water evaporates off of the skin heat is removed from the animal in order to break apart the hydrogen bonds in the water to cause the evaporation to occur.
2. Water does not cool down or heat up very quickly because of the hydrogen bonds. THis is useful because our bodies are composed in large part out of water and this allows us to maintain our body temperature at 37 degrees C.
What types of solutes will dissolve in water?
Since water is polar, polar and ionic solutes will dissolve in water.
How is the energy in ATP released?
The energy between the bonds in ATP is released when the molecule in hydrolyzed to form ADP (Adenosine diphosphate) and phospate.
How do proteins differ from each other?
The number and sequence of R groups in the protein.
If salt is dissolved in water to make a salt solution, which part is the solvent and which part is the solute?
Salt is the solute and
Water is the solvent.
What is the R group on an amino acid?
There are 20 different R groups that create 20 different amino acids. The R group is a functional group attached to the amino acid. The different R group makes the amino acids different.
Phosphate group?
Value for neutral pH?
Polymers formed by joining together many monosaccharides. For example many glucose molecules can join together to form the polysaccharides starch, glycogen and cellulose.
The total amount of kinetic energy (energy due to the movement of atoms and molecules) in a body of matter.
A molecule that contains carbon and hydrogen?
What holds the complementary base pairs together?
Hydrogen bonds.
Proteins are polymers made of long chains of amino acids.
Lipids with a distinctive 4 ring structure. Cholesterol is the starting steroid and others are created by adding different functional groups to this structure. Steroids often function as hormones in our body (eg. testosterone).
Organic Chemistry?
The study of organic (living) compounds. Organic compounds contain carbon and hydrogen.
Valence shell?
The outermost electron shell of an atom
An atom that has lost or gained electrons so that it has a charge. An atom that gains electrons becomes negatively charged and an atom that loses electrons becomes positively charged.
Dehydration synthesis?
The process in which monomers join together to form longer chains. During this process a water molecule is lost (dehydration) and a chain is created (synthesis).
The process in which polymers gain a water molecule (hydro) to break apart (lysis) a monomer from the polymer.
Monomer for Carbohydrates?
Simple sugars (monosacharides) are the monomers for carbohydrates. For example: Glucose, fructose, galactose.
ATP is a special nucleotide that acts as the energy currency of the cell. ATP (Adenosine triphosphate is composed of the nitrogenous base adenine, a ribose sugar and 3 phophate groups.
Functions of proteins?
Proteins have many many different functions:
1. Structural -- eg. for hair, feathers, making fibers for spider webs.
2. Storage of amino acids -- eg in egg white for developing embryo.
3. make up some hormones
4. make up enzymes, which speed up chemical reactions
5. used for defense system in attacking bacteria and viruses
A lipid molecule that is used for energy storage, warmth and some protection.
Ionic bond?
The bond that forms between a positive and negative ion.
Solution, Solvent, Solute?
A liquid consisting of a homogeneous mixture of two or more substances consisting of a dissolving agent called the solvent and the substance that is dissolved called the solute.
Monomers of phospholipids?
Contain a glycerol, 2 fatty acid chains and a phosphate group.
Deoxyribose versus Ribose sugar?
Deoxyribose is the sugar molecules found in DNA. They have one less oxygen than ribose sugar which is found in RNA.
Beta glucose in cellulose.
Notice that Beta glucose causes cellulose to have OH molecules on alternating sides.
Functional group?
Small groups that are added on to basic carbon skeletons. Each functional group has certain chemical characteristics that change the nature of the hydrocarbon.
Alpha glucose in starch.
Notice that Alpha glucose causes starch to have OH molecules all on one side.
Adhesion of water molecules?
The clinging of water molecules to another substance.
Where in animals does glycogen get stored?
In muscles and liver.
Complementary base pairing in DNA?
Complementary bases join together on either side of the DNA strand.
A always with T
G always with C
Monomers of fats?
The monomers in fats are one glycerol + 3 fatty acid chains.
Denaturation of a protein?
When the tertiary structure of a protein is disrupted.
What happens when the monosaccharides glucose and fructose molecules join together?
Glucose and fructose molecules join together through the process of dhydration synthesis to form Sucrose (a disaccharide).
Differences between DNA and RNA?
RNA versus DNA
RNA - Single strand DNA-Double strand
RNA-uracil DNA-thymine
RNA-ribose sugar DNA-deoxyribose sugar
RNA-shorter DNA-longer
When salt (NaCl) dissolves in water, what is actually happening?
The salt is breaking apart (dissociation) into its ion components.
What happens when 2 glucose (monosaccharides) molecules join together?
2 glucose molecules will join together through the process of dehydration synthesis to form Maltose (a disaccharide).
How do fats form?
When 3 fatty acid chains attach to a glycerol molecule through the process of dehydration synthesis a fat molecule is formed.
Secondary structure of a protein?
When proteins have an alpha helix or pleated sheet structure. These structures are held together by hydrogen bonds.
Primary structure of a protein?
The sequence of amino acids in protein which is held together by peptide bonds.
What is meant by the term "like dissolves like"?
Non-polar substances only dissolve in another non-polar solvent.
Polar or ionic substances will dissolve in a polar solvent
How much greater is the concentration of hydrogen ions in a solution with a pH of 2 than a solution with a pH of 7?
10x10x10x10x10 = 100 000 more hydrogen ions
What are the main elements in the human body?
Oxygen (65%), Carbon (18.5%), Hydrogen (9.5%), Nitrogen ( 3.3 %)
- remember CHON
Why do living organisms contain buffers?
So that the pH in the organism remains constant. Chemcal reactions that occur in organisms can't occur if the pH in the organism changes.
Give an example of a protein that has quaternary structure?
Hemoglobin, which is the molecule found in red blood cells that carries oxygen.
Why is cohesion of water important for living organisms?
1. It is important in plants when water gets pulled up from the roots because cohesion allows the water molecules to stick together.
2. Water bugs can "walk" on water due to cohesion of the water molecules.
Why is it important to living things that ice is less dense than water?
1. This is important for fish because it means lakes and ponds freeze on top but remain liquid underneath so that the fish survive.
2. Frozen ice sheets in the Arctic create hunting ground for polar bears and living space for other animals.
Why is it a problem if proteins become denatured?
When proteins become denatured they do not work properly because their 3 dimensional shape has been disrupted.
What are some ways to create diversity in hydrocarbons?
1. Vary the length of the carbon chain
2. Add branches to the carbon chain
3. Create ring structures with the carbon chain
4. add functional groups to the carbon chain.
What has a higher amount of heat: A 1 Litre container at 20 degrees C or a 5 Litre container at 20 degrees C?
The 5 litre container contains more heat because it is bigger and therefore has more energy because it has more molecules.
How does an atom gain stability in its outer shell?
By gaining or losing electrons so that the outer shell (valence shell) is full.
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