Unit One: Contents of the Cell

Question 1

Key Attributes of the Cell

Answer 1

• cell membrane
• system to store
• energy transferring pathways

Question 2

What is a Protobiant

Answer 2

• precursors to modern life
• non-living molecules
• group of abiotically produced molecules surrounded by membrane
• spontaneously formed

Question 3

Why are proteins more versitile than RNA?

Answer 3

1. Enzymes have a greater catalytic power to faciliate chemical reactions
   - enzymes catalyze 1000/s, ribozymes 1/10 speed
2. Cells **produce a large array of proteins **
   - 20 different AA, 4 nucloetides for RNA
3. Amino acids can cross interact among themselves
   - cannot mix and match nucelotide (base pairs)

Question 4

Why does DNA have better information storage than RNA

Answer 4

1. DNA is more stable than RNA
2. Nucleotide Composition
3. DNA is double stranded

Question 5

What are the major differences between prokaryotes and eukaryotes

2 major differences

Answer 5

1. Seperation of DNA and Cytoplasm (nuclear envelope)
2. Presence of membrane bound organelles found in cytoplasm

Question 6

What is the Theory of Endosymbiosis

Answer 6

• large prokaryotic cell engulfed by ancestral prokaryotes
• mutually advantageous
• mitochondria evolved from aeorobic bacteria
• chloroplasts evolved from cyanobacteria

Question 7

Features of Mitochondria and Chloroplasts

Answer 7

1. Morphology: shape size, and smaller to prokaryotes
2. Reproduction: derived from previous cell division (indivdually cannot synthesize newly
3. Genetic Information: both contain own DNA
4. Transcription + Translation: contain ribosomes and tRNA
5. Electron Transport: ETC and ATP synthase generates chemical energy
6. Sequence Analysis: close match with cyanobacteria and heterotrophic bacteria of DNA coding genes of the ribosome

Question 8

What is an Endomembrane System

Answer 8

• derived from plasma membrane
• intermembrane system seperating cells into functional components
• nuclear envelope (ER, GC)

Question 9

Energy Crisis: Bacteria and Archea

Answer 9

• structure and function conversed
• less energetic

Question 10

Energy Crisis: Eukaryotic Cells

Answer 10

• larger, more diverse, complex
• greater energetic needs
• larger genome

Question 11

Evolution of Multicellularity

Answer 11

• increased specialization and complexity
• 1.2 x 10^9 years ago
• evolution is not clear
• all cells are independent
• developed unique functions by cells
• lead to specialized tissue and organ

Question 12

What are the 2 sections of Gene Transfer

Answer 12

1. Vertical Gene Transfer (generation to generation)
   - inheriting genes from a previous generation
2. Horiztonal Gene Transfer (within a generation)
   - movement of genes across unrelated organism
   - common among viral and bacterial infections