Biochemistry CH 306 (chapter 1) Flashcards
What is meant by the phrase “unity of biochemistry”? What are the implications of the unity of biochemistry?
The phrase refers to the fact that all organisms are remarkably similar at a biochemical level, which strongly suggests that all organisms on Earth are derived from a common ancestor.
Describe the structural differences between DNA and RNA
DNA is double stranded, and its sugar is deoxyribose. DNA contains the base thymine. RNA is usually single stranded, and its sugar is ribose. RNA uses uracil in place of thymine.
Differentiate between proteins and glycogen in regard to their polymeric structure.
Proteins are linear polymers composed from 20 different amino acids. Glycogen is a branched polymer composed only of glucose.
Define the central dogma of biology.
The central dogma describes the fundamental information flow in biological systems. DNA is replicated to form new DNA, which is transcribed into RNA. The RNA is translated into protein.
Define replication, transcription, and translation in regard to the central dogma.
Replication is the generation of two daughter double helices from a single parent double helix. The process is catalyzed by
DNA polymerase. Transcription is the process of copying DNA information into RNA and is catalyzed by RNA polymerase. Translation converts the sequence information of RNA into proteins and takes place on ribosomes.
What is an enzyme?
An enzyme is usually a protein catalyst, although some types
of RNA also function as catalysts. Catalysts enhance the rate of a chemical reaction without themselves being permanently altered.
Differentiate between eukaryotic
cells and prokaryotic cells.
Eukaryotic cells contain a nucleus and a complex of membrane- bounded internal structures called organelles. Prokaryotic cells do not have a nucleus and lack the complex internal organization of eukaryotic cells.
What is an organelle?
An organelle can be any of a number of membrane-bounded structures inside eukaryotic cells.
Which organelles are surrounded by
two membranes?
Mitochondria, chloroplasts, and nuclei.
How does the nuclear membrane differ from other membranes?
The nuclear membrane is not continuous. It is a set of closed membranes that come together at pores.
Trace the pathway of the formation of a secretory protein from its gene to its exocytosis from the cell.
The gene is transcribed into RNA, which is translated into
the protein on ribosomes bound to the endoplasmic reticulum.
The protein enters the lumen of the endoplasmic reticulum, is sequestered into transport vesicles, and moves to the Golgi complex, where the protein is modified. The protein is packaged into secretory vesicles that fuse with the plasma membrane, resulting in the exocytosis of the protein.
Location of most of the cell’s DNA
Nucleus
Site of fuel oxidation
Mitochondrion
Separates the inside of the cell from the outside
Plasma membrane
Common form of cytoplasmic membrane
Endoplasmic reticulum
