Chapter 1: Central Dogma Flashcards
What is the central dogma?
information flows from DNA to RNA and then to protein. DNA can be replicated
What determines the physical nature of the organism?
Genes. DNA has the heritable information – the genome.
Define replication
When a cell duplicates, DNA is copied and identical genomes are then present in the newly formed daughter cells.
Copying of the genome is called replication.
Define transcription
To acctivate genes one form of nucleid acid, DNA, is transcribed into RNA.
What catalyzes transcription?
The enzyme RNA polymerase.
What catalyzes the replication process?
A group of enzymes, collectively called DNA polymerase
Define translation
Information is translated from one chemical form (nucleic acid) into another (protein).
Where does translation take place?
On large macromolecular complexes called ribosomes, consisting of RNA and protein
Define metabolism
the sum of all the enzyme-catalyzed reactions in a living organism
Define Anabolic (biosynthetic) pathways:
- Large complex molecules are synthesized from smaller molecules
- Requires energy
Define Catabolic pathways:
- Large complex molecules are degraded into simpler products
- Stores energy: a portion of the energy produced drives anabolic reactions
What do catabolism and anabolism share?
Both form intermediates that are shared among metabolic pathways
Which feature is essential for defining a system as “living”?
Ability to maintain homeostasis and respond to environmental changes.
Why do phospholipids form bilayers in aqueous environments?
The hydrophobic tails avoid water, while the hydrophilic heads interact with water, leading to a bilayer formation.
What are membranes consisted of?
a bilipid layer
define a bilipid layer
two layers of lipids organized with their hydrophobic chains interacting with one another and the hydrophilic head groups interacting with the environment.
What do membranes do?
Membranes define the cell and carry out cellular functions.
Provide a selective physical barrier, preventing contents from leaking out and other molecules from getting in.
What are the thrree domains of living organisms?
- Bacteria
- Archaea
- Eukarya
What are the three shapes of protaryotic cells?
- Rodlike (bacilli)
- Spheroidal (cocci)
- Coiled (spirilla)
Most prokaryotic cells contain what?
a cell wall made up of peptidoglycan.
What is the difference between Gram-negative and Gram-positive?
- A peptidoglycan rigid cell wall maintains shape and classifies the bacteria as Gram-positive.
- A peptidoglycan rigid cell wall and an outer lipid bilayer that classifies the bacteria as Gram-negative.
What are plasmids?
prokaryotic : Smaller circular DNA molecules separate from the chromosomes
What are pili
prokaryotic: Pili are fine hair-like structures that allow for attachment to food sources and host tissues.
