Unit 1: Properties of Cells Flashcards
What are 2 statements that describe the definition of a cell?
- A unit capable of carrying out essential life processes
- A unit that can usually reproduce
Which of the following structures do all cells share?
- cytoplasm
- ribosomes
- a membrane
- genetic material
What are two reasons that eukaryotic cells may have a nucleus.
- to keep processes like transcription separate from other processes like translation which allows for more complex ways to regulate gene expression than are possible in prokaryotes
- to keep all of the molecules necessary within the nucleus at a high concentration
What is cytoplasm in eukaryotic cells?
- the entire contents of the cell
What is cytosol in eukaryotic cells?
- the region inside the cell, but outside the organelles
Generally, what are the characteristics that define cells at the smallest unit of life. (3)
- all cells contain a stable blueprint of information in molecular form
- cells have a discrete boundary that separates the interior of the cell from its external environment
- cells have the ability to harness materials and energy from the environment
What are the 3 principles of the cell theory? Explain what this means.
- all organisms are composed of one or more cells
- the cell is the fundamental unit of life
- cells arise from pre-existing cells
- there is no life without cells and the cell is the smallest unit of life
Generally, which cells are bigger between bacterial cells and eukaryotic cells?
- eukaryotic cells are generally much bigger than bacterial cells
Elaborate on how all cells contain a stable blueprint of information in molecular form (4)
- nucleic acids store and transmit information needed for growth, function, and reproduction
- the central dogma of molecular biology
- organisms require an accessible and reliable archive of information that help determine their structure and metabolic activity
- organisms must have the ability to reproduce do cells must be able to copy their archive of information rapidly and accurately
replication
- the process of copying DNA so genetic information can be passed from cell to cell or from an organism to its progeny
transcription
- the synthesis of RNA from a DNA template
translation
- synthesis of polypeptide chain corresponding to the coding sequence present in a molecule of messenger RNA
central dogma (2)
- originally, the idea that information flows from nucleic acids to proteins, but not in the opposite direction
- more generally, the view that information transfer in a cell usually goes from DNA to RNA to protein
Elaborate on how cells have a discrete boundary that separates the interior of the cell from its external environment
- membranes define cells and spaces within cells
- membrane surrounds every cell and controls exchange of materials with the environment
plasma/cell membrane
- a membrane that surrounds the cytoplasm of the cell, separating the inside of the cell from the outside of the cell
cell wall (2)
- a structural layer external to the plasma membrane that helps maintain the shape and internal composition of the cell
- present in plants, fungi, many protists, archaeans, and bacteria