Week 11 Flashcards
Name characteristics of living things
- Have an Organized Structure
- Are Composed of Organic Molecules and Cells
- Grow and Reproduce (on their own!)
- Respond to the Environment and its Changes
- Have a Metabolism
◦ Take in Food
◦ Excrete Waste
◦ Maintains Homeostasis - Evolve and Adapt
Difference in prokaryote and eukrayotes accoridng to DNA , organelles, reproduction, average size
-
DNA:
- Prokaryotes: DNA is “naked” (not bound to proteins), circular, and usually lacks introns.
- Eukaryotes: DNA is bound to proteins, linear, and usually contains introns.
-
Organelles:
- Prokaryotes: No nucleus; no membrane-bound organelles; 70S ribosomes.
- Eukaryotes: Has a nucleus; membrane-bound organelles; 80S ribosomes.
-
Reproduction:
- Prokaryotes: Reproduce through binary fission; have a single chromosome (haploid).
- Eukaryotes: Reproduce through mitosis and meiosis; chromosomes are paired (diploid or more).
-
Average Size:
- Prokaryotes: Smaller (~1–5 µm).
- Eukaryotes: Larger (~10–100 µm).
This chart is a helpful summary for distinguishing these two types of cells.
What are the 4 major macromolecules and monomers prokaryote and eukaryote cells rely on ?
-
Protein
- Monomer: Amino acids
-
Nucleic Acids (DNA, RNA)
- Monomer: Nucleotides
-
Fats (Lipids)
- Monomer: Glycerol and fatty acids
-
Carbohydrates (Complex sugars)
- Monomer: Simple sugars (monosaccharides)
These macromolecules and their monomers play critical roles in the structure and function of cells across both cell types.
Monomer
(“one-part”): a small molecule that can covalently bind
to other similar molecules to form a larger molecule, called a macromolecule
◦ For example – amino acids, monosaccharides, nucleotides, fatty acids and glycerol
Polymer
Large number of monomers boded together
Macromolecule
Any very large organic molecule, usually made up
of smaller molecules called monomers that join together into a polymer. The main macromolecules are proteins, nucleic acids (DNA/RNA), and polysaccharides (e.g., starch, cellulose)
How did Eukaryotes airse
Endosymbiosis
Explain endosymbiosis
- Start with two independent bacteria.
- One bacterium engulfs the other.
- The engulfed bacterium begins to live inside the other.
- Both bacteria benefit from the arrangement—the internal bacterium provides additional functions, like energy production.
- The internal bacteria are passed on from generation to generation as part of the host cell, leading to the evolution of organelles like mitochondria and chloroplasts in eukaryotic cells.
This mutual relationship led to the development of complex eukaryotic cells from simpler prokaryotic ancestors.
Where did chloroplastes come from
Endosymbiosis
When did life originate
3.5 Billion years ago
When did the earliest fossils emerge and what is it
3.45 Billion YO
* Evidence from microfossils and stromatolites found in S.Africa and Australia
* Produced by mainly photosynthesizing bacteria…
* But even these were relatively complex compared to the earliest precursor molecules
What fundamental property of the universe does life defy
Entropy
What is entropy
The universal tendency towards disorder
Creating order from disorder requires inputs of…
…energy
Chemical evolution
Inputs of energy lead to the formation of increasinly complex carbon contaning substances
Chemical evolution (production)
Production of small organic (carbon-based) compounds from reactants such as atoms and simple molecules
Simple organic molecules form amino acids, nucleotides, sugars, & lipids
Macromolecules like DNA/RNA, proteins, complex carbohydrates form that are core components of life
4 Macromolecules of life
Carbohydrates
Lipids
Proteins
Nucleic acids