11. Describe the structure and properties of biological membranes.
Structure:
Barriers surrounding cells, regulating traffic in & out
Proteins/glycoproteins & lipids
Properties:
Semi-permeable
Amphipathic (parts nonpolar & polar)
Unsaturated fatty acids, loose environment
3. Classify nucleic acids.
DNA
Primary: Nucleotide base sequence
Secondary: 2 polynucleotides intertwine (like quaternary)
Double helix
Tertiary: Folding into chromosomes
Salt bridges neutralize negative charges of DNA backbone
RNA
mRNA
tRNA
rRNA
8. Describe the structure of chromosomes.
Folded & protein-coated compact structures
Each contain 2 polynucleotide strands (1 double helix)
DNA is stored in 46 chromosomes
In nucleus of cells
13. Describe the process of transcription.
Synthesis of RNA in nucleus (copying from DNA to mRNA)
13. Identify the properties and functions of cholesterol.
Functions: Component of membranes
Synthesized in liver
Starting material that makes other kinds of steroids/molecules
Correlation b/w high blood cholesterol & arteriosclerosis
4. Identify the components of nucleotides.
Building blocks of nucleotides:
Base: Heterocyclic nitrogen-containing ring
Purine (2 fused rings)
Adenine
Guanine
Pyrimidines: 1 ring
Thymine (DNA only)
Cytosine
Uracil (RNA only)
Sugar: Pentose monosaccharide
Beta D-Deoxyribose (carb) (DNA only)
2’ has H
W/out oxygen
Beta D-ribose (carb) (RNA only)
2’ has an OH
Phosphate: Inorganic phosphate
Phosphoric acid has 3 hydrogens
DNA/RNA favors phosphate w/ 1 hydrogen
9. Define genes and chromosome maps.
Genes: Segments of DNA within chromosomes
Chromosome maps: Show genes, proteins, traits, & diseases associated w/ sequence blocks on chromosomes (base pairs)
14. Describe the process of translation.
Synthesis of a protein w/ correct sequence using instructions in mRNA
Takes place in cytoplasm
tRNAs read the codon instructions in mRNAs, then deliver the amino acids to make proteins
15. Identify the properties and functions of steroid hormones.
Properties: 4 rings
Functions: Many functions
5. Identify the structural differences between DNA and RNA.
DNA: Phosphate, deoxyribose sugar, A, G, C, T bases
RNA: Phosphate, ribose sugar, A, G, C, U bases
10. Describe the process of DNA replication.
Semi-conservative
Each daughter double helix gets 1 parent polynucleotide strand
Enzyme unwinds helix to expose nucleotide bases
New DNA is built by linkijng nucleotides w/ bases complementary to exposed bases
15. Identify characteristics of the genetic code.
Genetic code: Converting Codons → into amino acids
Ex: UGG = Tryptophan
Characteristics:
3 Letter words
Degenerate (Muliple codons can represent 1 amino acid)
Precise (1 codon can represent only 1 amino acid)
Initiation (AUG = start)
Termination (Stop codons)
Universal (GCA is in basically every organism)
1. Identify nucleotides, dinucleotides and polynucleotides.
Nucleotides: Building blocks of nucleic acids
Building blocks of nucleotides:
Base: Heterocyclic nitrogen-containing ring
Sugar: Pentose monosaccharide
Phosphate: Inorganic phosphate
Looks like an amino acid w/ a common part + different bases
5’ terminal end phosphate
3’ terminal end hydroxyl
Dinucleotides: 2 nucleotides linked together
Polynucleotides: Nucleic acid (DNA or RNA)
Many nucleotides linked together
Very large
Order is important (like proteins)
6. Describe condensation reactions of nucleotides.
Condensation reaction to make nucleotides:
3 components connected by dehydration condensation
Sugar in middle b/w phosphate & base
Base connected to sugar (glycosidic); phosphate connected to sugar (phosphoester)
Makes 2 H2Os
Nucleotide dehydration condensation:
Phosphate of 1 nucleotide is linked to the sugar of another nucleotide
Bases not involved
11. Distinguish types of RNA (mRNA, tRNA, rRNA).
mRNA: Linear, extended
Transport recipes for proteins frp, nucleus to the cytoplasm where protein synthesis takes place
tRNA: Cloverleaf
Deliver correct amino acids for eahc position in the growing protein
rRNA: Folded structures
Components of ribosomes (sites of protein synthesis in cytoplasm)
2. Identify the importance of nucleic acids in biology.
Sequences of building blocks that store amino acid sequence info for proteins
DNA: Recipe for proteins
Transcription into RNA
RNA: Copy recipe info
Translation from RNA onto a protein (out of nucleus)
Translation is synthesis of protein in cytoplasm
Make a copy
Move it outside
Make protein (recipe)
7. Describe the structure, properties and functions of DNA.
Structure: 2 antiparallel polynucleotide strands twisted around (double helix)
Properties: Bases form hydrogen bonds (2 for A & T, 3 for C & G)
Functions: Store information in units (genes)
Genes provide function or determines characteristics
Basic physical & functional units of heredity
12. Define the Central Dogma of Molecular Biology.
When cells need to make copies for each cell
Information goes from DNA → RNA → Make a protein