Lecture 1: Cells Flashcards
Nucleotide
Monomers in DNA. A sugar (deoxyribose), a phosphate group, and a nitrogenous base (A,G,T,C). Each sugar linked via phosphate group.
Ribonucleic Acid (RNA)
the transcribed form of DNA that leads to the synthesis of proteins. backbone contains ribose instead of deoxyribose. Single stranded
Nucleic Acids
Long polymers of nucleotide monomers that are linked via phosphodiester bonds. (RNA and DNA)
Nucleotide
subunits of DNA and RNA. Contain nitrogenous base, five carbon sugar, and phosphate group or groups. (pyrimidines= Cytosine and Thymine, Purines=Guanine and Adenine)
nucleoside
nitrogenous base linked to sugar (No phosphates)
Ribonucleotide
Ex. ATP
Pyrimidines
6 membered ring. Cytosine and Thymine(and uracil).
Think Cut The Pie
Purine
Pyrimdine ring with an additional five membered ring attached (Adenine and Guanine)
mRNA
Encode protein, intermediate molecule that encodes a final product of proteins. Located in Cytosol and ER. Short lived and frequently produced and degraded. 3-5% of RNA in a eukaryotic cell.
tRNA
mRNA translation. Located in cytosol and ER
rRNA
mRNA translation. in Cytosol and ER. Majority of RNA is rRNA.
Transcriptional unit
one segment of DNA which is transcribed into a single product. most encode mRNA
snRNA
Small nuclear RNA. HAs role in splicing mRNA.
miRNA
Micro RNA. regulate gene expression. Endogenous
siRNA
Small interfering RNA. Regulate gene expression. Exogenous
RISC (RNA induced silencing complex)
uses ssRNA to complementary base pair with an mRNA molecule and inhibit translation or induces degradation.
Complementary base pairing
Pyrimidines Cytosine and Thymine pair with Purines Adenine and Guanine in DNA via non covalent H bonds.
Peptide bond
covalent bond between two adjacent amino acids and it is always between the positively charged amino and negativelty charged carboxyl groups.
AA’s with polar side chains
Aspartic acid, glutamic acid, arginine, lysine, histidine, asparagine glutamine, serine, threonine, tyrosine
Negatively charged side chains
Aspartic acid, Glutamic acid
Positively charged side chains
Arginine, Lysine, Histidine
Uncharged but polar side chains
Asparagine, Glutamine, serine, threonine, tyrosine
Condensation reaction
Forms a glycosidic bond between two free hydroxyls, one on each sugar. This reaction expels water
Hydrolysis
Addition of water reforms the free hydroxyl residues and splits the glycosidic bond.
Saturated
no double bonds
Unsaturated
Contain 1 or more double bonds.
Lipids
hydrophobic and insoluble in water.
Fatty acids
contains hydrophobic hydrocarbon chain/tail and a hydrophilic carboxyl group. hydrocarbon chain is either saturated (no double bonds) or unsaturated (1 or more double bonds).
Triacylglycerols
fatty acids stored in the cytoplasm. contain 3 fatty acid chains and a glycerol molecule. can be broken down for energy use into first free fatty acid chains and a glycerol molecule then again into two carbon units that are identical to those derived from glycolysis. Triacylglycerols are the preferred form of long term storage because they weigh far less than sugars.
Phospholipids
make up cell membranes and are composed of two fatty acid chains, glycerol, a hydrophilic phosphate group and a small hydrophilic group (most often choline). They are amphipathic -> contain a hydrophilic head and a hydrophobic tail portion. Make up lipid bilayer.
Amphipathic (or Amphiphilic)
contain both a hydrophilic portion and hydrophobic portion (like phospholipids)
Gram positive
Bacteria that contains several layers of peptidoglycan
Gram negative
single layer of peptidoglycan
Prokaryotes
Contain circular Chromosome. Bacteria. Contain rigid cell walls. No organelles. Archaebacteria exist in extreme environments while Eubacteria are the rest and contain diseaase causing bacteria. Cell walls consist of peptidoglycan.
Eukaryotes
More complex than Prokaryotes. Cells always surrounded by plasma membrane. Contains organelles and cytoskeleton. DNA is linear and in the nucleus.
Nascent
unfolded form of a protein.
Chaperones
Help fold a protein into final form that is more energetically favorable.
Aldehyde
-CHO, Involved in closing of sugar into ring when reacting with free hydroxyl on other terminus.
ATP (Adenosine Triphosphate)
A ribonucleotide used to store energy released during metabolic breakdown of ingested organic compounds. Energy is stored in the phosphoanhydride bonds between phosphate groups. Hydrolysis of these groups releases energy.
Carbohydrates
(CH2O)n. Sugars. Polymers of monosaccharides (disaccharides, oligosaccharides, and polysaccharides are formed by linking simple sugars together via condensation reactoin in which a glycosidic bond is formed between two free hydroyls. Used for cellular energy, especially glucose. (Glycogen in animals, starch in plans).
Cellulose
Mechanic support in plants. Linkages cannot be broken down by human digestive enzymes.
Deoxyribose
In DNA. Ribose that has 1 less oxygen
Disaccharide
2 monosaccharides linked by glycosidic bond
Enantiomers
Same formula but mirror images (D or L)
Essential Amino Acids
Threonine, Methionine, Lysine, Valine, Leucine, Isoleucine, Histidine, Phenylalanine, Tryptophan. Cannot be synthesized so must be consumed through diet.
Nitrogen fixation
the incorporation of nitrogen into organic molecules.Energetically expensive.
Glucose
C6H12O6. Most important monosaccharide used for cellular energy. Broken down into glycolosis to form ATP and other cofactors.
Glycolipids
lipids with carbohydrates attahced via glycosidic bonds
Glycolysis
break down of glucose and forms pyruvate with the production of two molecules of ATP
Glycoproteins
any of a class of proteins that have carbohydrate groups attached to the polypeptide chain
Hydroxyl
-OH
Isomer
Same formula, different structure ( Glucose and mannose)
Nucleoside Triphosphate
a type of nucleotide. contains a nucleoside bound to three phosphate groups
Oligosaccharide
3-10 sugars bound by glycosidic bond.
Phosphoanhydride bond
where energy is stored in ATP
ribose
five carbon sugar
starch
form of glucose stored in large polysaccharides in plants
