Unit 1- Origins and biomolecules

Question 1

Stanley Miller’s experiment

Answer 1

Simulated early Earth conditions to demonstrate the formation of organic molecules (e.g., amino acids) from inorganic precursors.

Question 2

RNA World Hypothesis

Answer 2

Suggests early life used RNA for both genetic information storage and catalysis before DNA and proteins.

Question 3

Evolution of metabolism

Answer 3

Metabolic pathways evolved from simple reactions to complex systems, supporting the rise of diverse life forms.

Question 4

Mitochondria and chloroplasts origin

Answer 4

Endosymbiosis theory: Eukaryotic cells acquired these organelles by engulfing free-living bacteria.

Question 5

Prokaryotes vs. Eukaryotes

Answer 5

P- No nucleus, single cell, small & simple
E- Nucleus, organelles, larger, and complex

Question 6

Types of bonds

Answer 6

Covalent: Strong, shared electron pairs.
Ionic: Attraction between charged ions.
Hydrogen: Attraction between partially charged hydrogen and another atom.

Question 7

Molecule types

Answer 7

Hydrophilic: Water-attracting.
Hydrophobic: Water-repelling.
Amphipathic: Both hydrophilic and hydrophobic regions.

Question 8

Macromolecule functions

Answer 8

Carbohydrates: Energy, structure.
Lipids: Membranes, energy storage.
Nucleic acids: Genetic information.
Proteins: Catalysis, structure, signaling.

Question 9

Macromolecule reactions

Answer 9

Build: Dehydration synthesis.
Break down: Hydrolysis.

Question 10

Carbohydrate structure:

Answer 10

Carbon chains with hydroxyl groups, linked by glycosidic bonds.

Question 11

Complex sugars

Answer 11

Starch: Energy storage (easy to break down).
Cellulose: Structural support (harder to break down).

Question 12

phospholipids

Answer 12

Common features: Hydrophilic head, hydrophobic tail.
Unique lipid: Sphingolipid (involved in cell signaling).

Question 13

Triglyceride structure

Answer 13

Glycerol backbone with three fatty acids.

Question 14

glycolipid

Answer 14

Lipid head with glucose

Question 15

DNA vs RNA

Answer 15

DNA: Double-stranded, stores genetic info.
RNA: Single-stranded, involved in protein synthesis.

Question 16

Nucleotide bonds

Answer 16

phosphodiester bonds

Question 17

Nucleic Acid Types

Answer 17

Nucleic acid: DNA/RNA.
Nucleotide: Monomer of DNA/RNA.
Nucleoside: Base + sugar (no phosphate).

Question 18

Purines vs. Pyrimidines

Answer 18

Purines: Adenine (A), Guanine (G).
Pyrimidines: Cytosine (C), Thymine (T), Uracil (U).