Module 1A Cells and Genomes Flashcards
the study of the structure, function, and behavior of cells.
Cell biology
Who said, “the key to every biological problem must finally be sought in the cell; for every living organism is, or at some time has been, a cell.”
E.B. Wilson
What fundamental similarity exists among living organisms despite their diversity?
living things are fundamentally similar inside
distinguishes life from other processes, as it involves a link between the characteristics of parents and their offspring.
heredity
Where do all living cells on Earth store their hereditary information?
double-stranded molecules of DNA
double-stranded molecules which are long, unbranched, paired polymer chains made of the same four types of monomers.
Deoxyribonucleic acid (DNA)
What is the process by which all cells replicate their hereditary information?
templated polymerization using double-stranded DNA molecules
A __ is the monomer of DNA, consisting of a sugar (deoxyribose) with a phosphate group attached and a nitrogenous base.
nucleotide
A nucleotide is the monomer of DNA, consisting of a __(__) with a __ attached and a __.
- sugar (deoxyribose)
- phosphate group
- nitrogenous base
What are the four bases found in DNA? (4)
- adenine (A)
- guanine (G)
- cytosine (C)
- thymine (T)
- transcribes portions of hereditary information from DNA and serves as an intermediary in the transfer of genetic information, guiding the synthesis of proteins.
- molecules can have unique shapes that enable them to recognize and bind to other molecules selectively.
Ribonucleic acid (RNA)
RNA contains ribose sugar and __(_) instead of thymine (T) found in DNA. __ are mass-produced, disposable intermediates.
- uracil (U)
- RNA transcripts
What are the two main processes involved in the expression of DNA information? (2)
- transcription (DNA to RNA)
- translation (RNA to proteins).
- act as catalysts that facilitate and accelerate chemical reactions in cells.
- carry information in the form of a linear sequence of symbols, which corresponds to their amino acid sequence.
proteins
The monomer of proteins is the __, of which there are __ different types.
- amino acid
- 20
- a protein molecule created by joining amino acids in a specific sequence.
- chains of amino acids linked by peptide bonds.
- a long, continuous, unbranched peptide chain.
polypeptide
a living cell contains various proteins that catalyze chemical reactions necessary for its __ and __ processes.
- replication
- metabolic
a segment of DNA sequence that corresponds to a single protein, a set of alternative protein variants, or a single catalytic regulatory, or structural RNA molecule.
gene
Each protein is encoded by a specific __, which determines the protein’s amino acid sequence and, consequently, its function.
gene
The expression of individual genes is regulated by __ sequences that are interspersed among the segments that code for proteins.
regulatory DNA
What types of molecules can a gene correspond to besides proteins? (2)
- catalytic regulatory RNAs
- structural RNAs.
The __ encloses each cell and acts as a selective barrier, regulating the passage of nutrients and waste materials.
plasma membrane
The plasma membrane is __, consisting of both hydrophobic (water-insoluble) and hydrophilic (water-soluble) parts, creating a bilayer.
amphiphilic
largely determine which molecules can enter or exit the cell, facilitating selective transport across the plasma membrane.
Membrane transport proteins
What is the minimum number of genes required for a viable cell to exist?
Not less than 300 genes.
- Which organism is known for having one of the smallest genomes with around 530 genes?
- Out of these genes, how many are considered essential?
- Mycoplasma genitalium
- Approximately 400 genes.
How can scientists characterize, catalog, and compare organisms today?
analyzing DNA sequence through standard biochemical techniques.
A cell that feeds on organic chemicals from other living organisms.
organotrophic
A cell that feeds on sunlight for energy.
phototrophic
A cell that feeds on rock or inorganic substrates
lithotrophic
Which six elements make up DNA, RNA, and proteins? (6)
- Hydrogen
- carbon
- nitrogen
- oxygen
- sulfur
- phosphorus.
Do eukaryotic or prokaryotic cells show greater biochemical diversity?
Prokaryotic cells
How do prokaryotic cells usually live?
As independent individuals or in loosely organized communities.
cells that can live in an enormous variety of ecological niches.
prokaryotic cells
What are the three primary branches of the Tree of Life? (3)
Bacteria, Archaea, and Eukaryotes.
What are the two distinct groups within prokaryotes?
Bacteria and Archaea.