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63 Cards in this Set
- Front
- Back
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What are the 4 functions of lipids? |
1. Long term nutrient and energy storage 2. Insulation and cushioning of internal organs 3. Form hormones to send messages throughout the body 4. Are a structural component of cell membranes |
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For the lipid function of energy storage: 1gram of lipid contains how many times as much energy as 1gram of carb? |
1gram of lipid contains 2.25 times as much energy as 1gram of carb |
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Triglycerides (fat molecules) have the same basic structure. Name 2 of their common structural characteristics: |
1. Glycerol (a triol/3-carbon alcohol), which is attached to... 2. 3 molecules of fatty acid |
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The 3 fatty acid molecules (found in fat molecules and triglycerides) are made of: |
Hydrocarbon chains attached to a carboxyl group (COOH). (They may be saturated or unsaturated.) (Only single/double bonded) |
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Name 2 characteristics of the Phospholipid structure: |
1. glycerol, two fatty acids and phosphate group 2. bilayer (hydrophobic interactions lead to its arrangement) (bilayer is the main fabric of biological membranes) |
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What makes up steroid structure: |
4 fused sterol rings |
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Which lipid group does cholesterol belong to? |
Cholesterol is a steroid. |
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Cholesterol is a common component of: |
The cell membrane |
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Cholesterol forms many ... |
Hormones. |
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What are the two things which nucleic acids direct? |
Growth and development of all life (by means of a chemical code) |
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What are the 2 nucleic acids? |
●RNA (ribonucleic acid) [single strand] ●DNA (deoxyribonucleic acid) [double strand] |
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DNA is the main component of: |
Genes/hereditary material |
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Instructions for making RNA are found in: |
Genes |
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Instructions for making proteins are found in: |
RNA |
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The sub-units of nucleic acids are: |
Nucleotides (we have millions) |
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In dehydration synthesis, Nucleotides are linked together by what type of bonds? |
Covalent bonds |
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What are the 3 components of a DNA molecule (nucleotide)? |
1. A phosphate group 2. Deoxyribose (a 5-carbon sugar) 3. A nitrogen base (A,T,GA, C) |
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What are the 4 nitrogen bases found in DNA? |
Adenine Thymine Guanine Cytosine |
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The 2 strands of DNA are linked using: |
Complementary base pairing and H bonds |
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A-T is held by how many H bonds? |
2 |
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C-G is held by how many H bonds? |
3 |
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DNA was first isolated when and by whom? |
1869 By Johann Friedrich Miescher |
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DNA molecules are named nucleic acids by whom and because: |
By Johann Friedrich Miescher Because they are acidic and found in the nucleus. |
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Nucleotides (bases) are joined together in what shape? |
Long chain |
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The sugar of one nucleotide is bonded to what of the next? |
The sugar of one nucleotide is bonded to the phosphate group of the next nucleotide. |
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The sequence of a nucleotide chain has a definite direction because: |
The sugar of one nucleotide is always bonded to the phosphate group of the next nucleotide. |
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Define the 5' end: |
Five prime end: The end of a nucleotide chain with a phosphate group exposed. |
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Define the 3' end: |
Three prime end: The end of a nucleotide chain with sugar exposed. |
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Who determined the 3D structure of DNA? |
James Watson and Francis Crick |
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What information found by Erwin Chargaff lead to Watson and Crick's discovery? |
Found the complementary base pairing in DNA. |
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What information found by Rosalind Franklin lead to Watson and Crick's discovery? |
X-rayed DNA, showed DNA was made of repeating structures. |
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What did Watson and Crick conclude about the 3D structure of DNA? |
DNA is made of 2 long chains of nucleotides arranged in a spiral. (Twisted ladder/double helix) |
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What are the sides of the DNA ladder made of? |
Alternating sugar and phosphate molecules. |
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What are the rungs of the DNA ladder made of? |
Complementary bases (A-T and C-G) held together by H-bonds. (These bases are nucleotides and letters of the genetic alphabet) |
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The 2 strands of DNA are described as: |
complementary (partner strands) |
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The sequence of amino acids in a protein chain determines what? |
Which protein will be formed. |
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In 1961, what hypothesis was proposed by Crick and his colleagues (one that changed the course of biological research)? |
A series of 3 nucleotides codes for 1 amino acid. (If 3 bases code for an amino acid, 64 possibilities exist) The sequences of bases in DNA make up codes for specific amino acids in a protein chain. |
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A series of 3 nucleotides is also referred to as (2 names): |
Triplet Codon |
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What is the "Alphabet" of DNA triplets? |
Consists of DNA triplets that code for specific amino acids. |
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In order for a new cell to function properly, what must it contain? |
A complete set of genetic instructions. |
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Genetic instructions are carried on what? Because of this, what is critical? |
On DNA molecules. It is critical that every new cell receive an exact copy of its preceder's DNA molecule. |
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DNA code is copied how? |
By process of replication. |
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What happens during replication? |
New strands of DNA are synthesized from a supply of nucleotides in the nucleus. |
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Base pairing proceeds in (/enzymes only work in) what direction on a particular strand? |
Each new strand grows from the 5' end to the 3' end. |
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Each daughter DNA molecule consists of what? What is the name of this model? |
One parent and one newly made strand. Semi conservative. |
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Bases are attached to which end of a DNA strand in order and which end in segments? |
5' end (phosphate) in order 3' end (sugar) in segments |
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What does the process of replication ensure? |
The exact order of bases in a DNA molecule will be preserved and passed down from one generation of cells to the next. |
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Explain the relationship between the daughter and parental DNA strand: |
Two DNA strands separate and each strand is used as a template for the assembly of a complementary strand. |
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Components of fat molecules/triglycerides are linked through: |
Dehydration synthesis |
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Are triglycerides polar or nonpolar? |
triglycerides are nonpolar (will not be attracted to or dissolve in polar molecules) |
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What is the alphabet of DNA triplets called? |
The genetic code |
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What are the 3 types of lipids we have discussed? |
Triglycerides Phospholipids Steroids |
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Base pairing errors occur at a frequency of: |
1 in 10,000 |
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Which bacteria checks and replaces incorrect nucleotides? |
Bacteria DNA polymerase |
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Mutations in DNA can be caused by: |
Chemicals and radiation, which DNA is constantly subjected to. |
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Because of frequent mutations in DNA, what exists to prevent them? |
DNA repair enzymes (such as DNA polymerase and ligase) |
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What is Xeroderma Pigmentosum? |
Genetic disease producing dejective repair enzymes used in skin repair. |
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The base that replaces Thymine in RNA is: |
Uracil |
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What is transcription? |
DNA to mRNA (messenger RNA) [uses RNA polymerase and uracil] |
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What is mRNA? |
Messenger RNA conveys genetic info from DNA to the ribosome where they specify amino acid sequence. |
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What is translation? |
mRNA to protein [Uses mRNA codons, tRNA anticodons, ribosomes (rRNA) |
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Explain the two steps of DNA replication: 1. Unzips 2. Re-formed |
1. Enzymes break H-bonds between complementary base pairs. Separation of strands occurs at many places at same time. DNA helix opens, exposing bases. Enzymes catalyze pairing of free-floating nucleotides to now exposed bases. 2. Peptide bonds (phosphate of one nucleotide to sugar of the next) re-formed by enzymes. Helix coils. |
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Sites at which separation and replication occur are called: |
Replication forks |
