Chapter 2 -> Chemical Components of Cells Flashcards
The Chemistry of Life is based on…
1) Carbon compounds
2) Chemical reactions that take place almost exclusively in water
3) The complexity
4) Collections of large polymers
5) Tightly regulated systems
What is the definition of an atom
The smallest particle of an element that still retains its distinctive chemical properties
What particle in an atom determines whether a nucleus may disintegrate by radioactive decay?
Neutrons
What isotope of carbon is used to determine the age of organic material?
Carbon 14
How do you find the atomic weight/ molecular weight of an atom?
Add the protons plus the neutrons
How many naturally occurring elements are there?
90
96% of living things’ total body weights are made of what four elements?
Carbon, Hydrogen, Oxygen, and Nitrogen
What other additional 7 elements besides CHON made up 0.9% of our total number of atoms?
S, Na, P, Mg, K, Ca, Cl
What is the definition of a noncovalent hydrogen bond?
A slightly positively charged hydrogen atom that is electrically attracted to the slight negative charge of the oxygen
Strength of Bonds from Strongest to Weakest
Covalent
Noncovalent: Ionic Bond
Noncovalent: Hydrogen Bond
Noncovalent: Van Der Waals Attraction
What force plays an important role in building the cell membrane?
Hydrophobic Forces
Definition of an Acid
Substance that releases protons when dissolved in water, forming H3O+ (AKA the H+ concentration)
Definition of Bases
Molecules that readily accept protons when dissolved in water
Definition of a buffer
Mixtures of weak acids and bases that will adjust proton concentrations by releasing protons or taking them up
What two Substances make up the majority of the chemical composition in a bacterial cell?
Water (70%) of the cell weight
and Macromolecules (24% of the cell weight)
What are the Four Major Families of small organic molecules that make up the macromolecules and what do their weights range from?
Also, up to how many carbon atoms can they contain?
Fatty Acids, Sugars, Amino Acids, and Nucleotides, Molecular weights in the range 100-1000 and can contain up to 30 Carbon Atoms
Where are small organic molecules typically found and what 2 roles can they play?
Found floating in cytosol
- Used as monomer subunits to construct macromolecules
- Used for energy by being broken down into other molecules (metabolism)
Nearly how many different kinds of organic molecules have been detected in E. coli?
4,000
Monosaccharides Definition and provide an example
- Simplest Sugars
- Example: Glucose
- Typical formula is (CH2O)n where n is 3,4,5, or 6
- make the larger CARBOHYDRATES
Glucose, a monosaccharide, can be converted into what two sugars by simply switching the orientation of -OH groups
Important Note: these 3 sugars can exist in either D-form or L-form which are mirror images of each other and these are called ISOMERS
Mannose or Galactose
What bonds link monosaccharides together?
What is the name for two monosaccharides after they have been linked together and what is an example?
Covalent bonds- in particular glycosidic bonds
Disaccharides-Sucrose is an example (Glucose + Fructose)
Polysaccharides Definition
Thousands of monosaccharides linked together
In a condensation reaction (The LINKING of two molecules), what groups come together and what is expelled as a by product?
Two -OH groups come together and H2O is expelled
(OH + OH)
(O and H2O)
During the process of hydrolysis (ENERGETICALLY FAVORABLE), what molecule is consumed to the break a bond?
Water
What is the term for long-term glucose storage in Animals? In plants?
Glycogen
Starch
What polysaccharide of glucose in the most abundant organic molecule on earth?
What’s another organic substance that is found in insect exoskeletons and fungi
Cellulose
Chitin
What does the linking of oligosaccharides and proteins form?
What does the linking of oligosaccharides and lipids form?
Glycoproteins
Glycolipids
What forms the molecular basis for the human blood groups?
Sugars found on the surface of cells
What are the two chemically distinctive regions of a fatty acid?
Are they hydrophobic or hydrophilic?
What part of the molecule is linked to another fatty acid?
1) Long hydrocarbon chain that is hydrophobic and NOT chemically reactive
2) Carboxyl Group (-COOH) that is hydrophilic and VERY reactive
The carboxyl heads
What is the term for a molecule that posses both hydrophilic and hydrophobic regions?
Amphipathic
Is Palmitic acid saturated or unsaturated, and what the hell does that even mean?
It is saturated, meaning it has NO double bonds between its carbon atoms and contains the MAX # of hydrogens
What is an example of an unsaturated fatty acid and what does it look like?
Oleic acid- has kinks in hydrocarbon tail from the double bonds and therefore affects fluidity in cell membranes
What makes one fatty acid different from the next?
The length of their tails as well as where the double bonds (if there are any) are placed
Fatty acids can be broken down to produce around ____ times as much usable energy as glucose can
6
Where are fatty acids stored and what are they stored as?
Stored in cytoplasm as droplets of Triacylglycerol (three fatty acid chains joined to a glycerol molecule)
What are triclyglycerols?
The animal fats found in meat, butter and cream as well as the plant oils (HYDROPHOBIC)
What are lipids soluble in?
Fat and organic solvents like benzene
Phospholipids - the one’s that make up the cell membrane- are composed of what?
Phospholipids vs. Triacylglycerols
The third site on the glycerol head is linked to what instead of another tail?
Fatty acids and glycerol molecules
Same glycerol head, different number of tails (2 vs. 3)
Third site on glycerol is linked to a small hydrophilic compound like choline
What aspect of a phospholipid’s nature makes it so readily form membranes in water?
Its amphipathic nature (Hydrophobes come together and hydrophilics stay near the water hence the double membrane layer shit)
What is the defining property of an amino acid?
They all posses a carboxylic acid group and an amino group that are attached to a central alpha carbon
What are the bonds that form between proteins called
Peptide bonds
Polypeptides always have an _______ group on one end AKA as the ________, and a __________ group on the other end AKA _____
Amino, N-terminus
Carboxyl, C-terminus
All amino acids except ______ exist as optical isomers in D and L forms
Glycine
Which optical isomer form is only found in proteins?
L-forms
DNA and RNA are built from subunits called ________
Nucleotides
Nucleotides consist of a nitrogen-containing ring compound linked to a 5-carbon sugar that has one or more phosphate groups attached
The sugar can be either -________ (2 -OH groups) or _______ (1 -OH group)
Ribose, Deoxyribose
Definition of a ribonucleotide
Contains ribose
Definition of a Deoxyribonucleotides
Contains deoxyribose
What are the 3 pyrimidines?
Do they have one ring or two?
Cytosine, Thymine, and Uracil
One Ring
What are the two Purines?
Do they have one ring or two?
Adenine and Guanine
Two rings
What is a nucleoside?
A base + sugar WITHOUT phosphate group attached
What is the fundamental role of nucleotides?
The storage and retrieval of biological information
Nucleotide subunits are linked by the formation of covalent _____________ bonds between the sugar of one nucleotide and the phosphate group of another
Phosphodiester
What are the two main types of nucleic acids, which differ in the type of sugar contained in their sugar-phosphate backbone?
What bases do they have?
Ribonucleic Acids -> A, G, C, and U
Deoxyribonucleic Acids -> A, G, C, and T
What is the technical name for ATP
What is the structure of an ATP molecule?
Ribonucleotide Adenosine Triphosphate
Three phosphates linked by two phosphanhydride bonds
What are the 3 functions of Proteins?
1) Act as Enzymes
2) Used to build cell structure
3) Act as molecular motors
What type of bonds specify the precise shape of a macromolecule?
Non-covalent
How is a protein able to act as an enzyme?
The specificity in bonding of a macromolecule to other molecules allows this
Are Triacylglycerolds Amphipathic?
No, they are mainly hydrophobic
How is ATP formed?
Formed in reactions driven by energy released by breakdown of food
What type of bond linked the three phosphates together on ATP?
Phosphoanhydride Bonds
What determines what a macromolecule can bind to?
its 3D shape as well as the location of its charges
What allows a protein to act as an enzyme?
The specificity in bonding of a macromolecule to other molecules
