Biomolecules and Protein Synthesis Flashcards
Types of chemical bonding
ionic, covalent, hydrogen
Ionic bond (what it is, electronegativity, example)
- Electron is transferred from one element to another
- Electronegativity: one strong, one weak
- between 2 ions with opposite charges
- Ex: Nacl
Covalent bond (what it is, electronegativity, examples)
- electrons are shared
- electronegativity is relatively equal
- non-polar: equal sharing ex: CH4
- polar: unequal sharing ex: H2O
Hydrogen bond (what it is, examples)
- opposite partial charges on adjacent molecules –> attraction
- slight (+) charges (near H) and (-) charges (near O) –> attraction
ex: water molecules binding to each other
Biomolecules (3 points)
- molecules synthesized by cells
- contain c-c covalent bonds
- often form ring or chain structures
How do we make biomolecules?
Dehydration synthesis: forming covalent bonds by removal of H2O
How do we break biomolecules?
hydrolysis: breaking covalent bonds by the addition of water
Types of biomolecules
carbohydrates, lipids, proteins, nucleic acids
Carbohydrates (contain, properties, types)
Contain: C,H,O (C+H2O)
Properties: polar –> hydrophilic
Types: simples sugars, complex carbohydrates
Simple sugars (function, types, examples)
function: fast energy
Types:
-monosaccharide: one sugar (glucose, fructose)
-disaccharide: two sugars (sucrose, lactose)
Complex carbohydrates (function, type, examples)
Function: energy storage, structural support, component of cell membranes
types:
-polysaccharide: chain of sugars (starch, glycogen, cellulose, chitin)
Lipids (contain, properties, types)
Contain: C,H,O properties: non-polar --> hydrophobic Types: -Triglycerides -Phospholipids -Eiconosids -Steroids
Triglycerides (structure, function, types)
Structure: glycerol, 3 fatty acid chains Function: energy storage, insulation, protection Types: 1. saturated -no double bonds -tightly packed -solid at room temperature 2. unsaturated -contains double bonds -loosely packed -liquid at room temperature
Phospholipids (structure, function)
Structure: -glycerol -phosphate group (polar) -two fatty acid tails (non-polar) Function: membrane structure
Eiconosids (structure, function, example)
Structure: -ring structure -fatty acids Function: cellular communication Example: Prostaglandin (pain perception)
Sterols (structure, function, examples)
Structure: -4 carbon rings with side chains -all derived from cholesterol Function: -membrane fluidity -cellular communication -others Examples: - cholesterol, testosterone, vitamin D
Proteins (contain, structure, function)
Contain: C,H,O,N Structure: chain of folded amino acids (polypeptide) Function: -structural support -enzymatic activity -chemical messengers -receptors
Amino acid structure
- central carbon
- amino group: NH2
- carboxyl group: COOH
- R group: determines amino acid
Protein structural levels
- primary: sequence of amino acids (peptide bonds)
- secondary: structural motifs (H bonds)
- Alpha-helix: spirals
- Beta-pleaded sheets: pleads - tertiary: large scale motifs formed by the interactions between R-groups (H-bonds, ionic bonds, disulfide bonds)
- quaternary: bonding with multiple polypeptide chains
Nucleic acids (contain, properties, structure, function, types)
Contain: C,H,O,N,p Properties: polar --> hydrophilic Structure: chain of nucleotides Function: 1. store genetic information (DNA) 2. DNA expression (RNA) Types: DNA, RNA
Nucleotide (what is it made of)
- phosphate group
- Nitrogenous base
- adenine, guanine, cytosine, thymine (DNA), uracil (RNA)
DNA (structure, sugar, what binds to adenine)
- double stranded helix
- sugar: deoxyribose
- thymine binds to adenine
RNA (structure, sugar, what binds to adenine, types)
- single stranded
- sugar: ribose
- uracil binds to adenine
- types:
- mRNA: messenger RNA, nucelus –> ribosome
- tRNA: transfer RNA, important in protein synthesis
- rRNA: ribosomal RNA, part of the ribosome
Plasma Membrane
- Structure: lipid bilayer with scattered proteins and cholesterol molecules
- Function: maintains boundary of cell and integrity of cell structure: embedded proteins serve multiple functions
Nucleus
- Structure: Surrounded by double layered nuclear envelope
* Function: houses the DNA, which dictates cellular function in protein synthesis
Nucleolus
- Structure: Dark oval structure inside the nucleus
* Function: synthesis of ribosomal DNA
Cytosol
- Structure: gel-like fluid
* Function: cell metabolism; storage
Rough Endoplasmic Reticulum
- Structure: continuous with the nuclear envelope; flattened stacks dotted with ribosomes
- Function: protein synthesis and post-translational processing
Smooth Endoplasmic Reticulum
- Structure: continuous with rough endoplasmic reticulum; tubular structure without ribosomes
- Function: lipid synthesis and post-translational processing of proteins; transport of molecules from endoplasmic reticulum in Golgi apparatus, calcium storage
Golgi Apparatus
- Structure: series of flattened sacs near the endoplasmic reticulum
- Function: post-translational processing; packaging and sorting of proteins
Mitochondria
- Structure: oval shaped with outer membrane and an inner membrane with folds called cristae that project into the matrix
- Function: ATP synthesis
Lysosomes
- Structure: granular, saclike; scattered throughout cytoplasm
- Function: breakdown of cellular and extracellular debris
Peroxisomes
- Structure: similar in appearance to lysosomes, but smaller
* Function: breakdown of toxic substances, including hydrogen peroxide
Vaults
- Structure: small, barrel-shaped
* Function: unknown; possibly transport of molecules between nucleus and cytoplasm
Ribosomes
- Structure: granular organelles composed of proteins and rRNA- located in cytosol or on surface of rough endoplasmic reticulum
- Function: translation of mRNA to synthesize proteins
Centrioles
- Structure: two cylindrical bundles of protein filaments that are perpendicular to each other
- Function: direction of mitotic spindle development during cell division
Cytoskeleton
- Structure: composed of protein filaments, including microfilaments, intermediate filaments, and microtubules
- Function: Structural support of cell; movement and contraction
DNA Replication (what is made, location, enzymes, semi-conservative, direction)
- DNA–>DNA
- Location: nucleus
- Semi-conservative: one old strand, one new strand
- Bidirectional
- Enzymes involved:
- Helicase: unwind double helix
- DNA Polymerase: add nucleotides to each unwound string of DNA
- can only add in 5’ –> 3’ direction
Protein Synthesis
Central dogma of molecular biology
DNA —> mRNA —> protein
DNA —> mRNA
transcription
mRNA —> protein
translation
Transcription (what is made, location, enzymes)
- DNA–> mRNA
- Location: nucelus
- Enzymes involved:
- RNA polymerase: unwinds DNA, makes a complimentary RNA strand to DNA
Genetic Code (codes for, how many codons, start/stop codons)
- mRNA language are codons (groups of 3 nucleotides)
- each codes for:
- amino acid (sense)
- stop-signal (non-sense)
- 64 possible codons, but only 20 amino acids
- Degeneracy: multiple codes for one amino acid
- Start codon: AUG (methionine)
- Stop codons: UAG, UAA, UGA
Translation (what is made, location, organelle involved)
- mRNA –> protein
- Location: cytoplasm
- organelle involved: ribosome
Translation Process
- mRNA becomes associated with ribosome
- start codon is exposed, and tRNA with complimentary anticodon binds
- tRNA have a specific anticodon and are attached to a specific aa - next codon of mRNA is exposed and tRNA binds
- peptide bond forms between aa
- ribosome moves along mRNA to expose another codon
- process repeats until stop codon
