The Cell Flashcards
Eukaryotic cells have:
- a membrane-bound nucleus
- numerous membrane-bound organelles
- rod-shaped chromosomes
Means “little organ”; have specialized cellular functions
Organelles
A phospholipid bilayer with embedded proteins that separates the internal contents of the cell from its surrounding environment; controls the passage of organic molecules, ions, water, and oxygen into and out of the cell
Plasma membrane
A lipid molecule with two fatty acid chains and a phosphate-containing group
Phospholipid
The cell’s entire region between the plasma membrane and the nuclear envelope
Cytoplasm
Percent of water consisting the cytoplasm
70% to 80%
T or F: The cytoplasm has a semi-solid consistency.
True
Houses the cell’s DNA and directs the synthesis of ribosomes and proteins
Nucleus
A double-membrane structure that constitutes the nucleus’ outermost portion; punctuated with pores that control the passage of ions, molecules, and RNA
Nuclear envelope
Semi-solid fluid inside the nucleus, where the chromatin and nucleolus can be found
Nucleoplasm
Structures within the nucleus that are made up of DNA
Chromosomes
Number of chromosomes in humans
46
Number of chromosomes in fruit flies
8
Describes the material that makes up the chromosomes both when condensed and decondensed
Chromatin
A darkly staining area within the nucleus that aggregates the ribosomal RNA with associated proteins to assemble the ribosomal subunits that are then transported out through the pores in the nuclear envelope to the cytoplasm
Nucleolus
The cellular structures responsible for protein synthesis
Ribosomes
Clusters of ribosomes
Polyribosomes
Travels to the ribosomes, which translate the code provided by the sequence
Messenger RNA (mRNA)
“Powerhouse” or “energy” factories of both plants and animal cells; responsible for making ATP
Mitochondria
The cell’s main energy-carrying molcule; represents the cell’s short-term stored energy
Adenosine triphosphate (ATP)
The process of making ATP using the chemical energy in glucose and other nutrients; a process that uses oxygen and produces carbon dioxide
Cellular respiration
Small, round organelles enclosed by single membranes; carry out oxidation reactions that break down fatty acids and amino acids; detoxify many poisons
Peroxisomes
Specialized peroxisomes in plants; responsible for converting stored fats into sugars
Glyoxysomes
Membrane-bound sacs that function in storage and transport
Vesicles and vacuoles
Can fuse with either the plasma membrane or other membrane systems within the cell
Vesicle membranes
Both plant and animal cells have
Microtubule organizing centers (MTOCs)
Present in plant cells but not in animal cells:
- Cell wall
- Chloroplast and specialized plastids
- Central vacuole
A microtubule-organizing center found near the nuclei of animal cells; contains a pair of centrioles; replicates itself before a cell divides; have a role in pulling the duplicated chromosomes to opposite ends of the dividing cell
Centrosome
Two structures that lie perpendicular to each other; each of these is a cylinder of nine triplets of microtubules
Centrioles
The cell’s “garbage disposal”; aid in breaking down proteins, polysaccharides, lipids, nucleic acids, and even worn-out organelles; have more acidic pH
Lysosomes
A rigid covering that protects the cell, provides structural support, and gives the shape to the cell
Cell wall
The prokaryotic cell walls’ chief component
Peptidoglycan
The major organic molecule in the plant cell wall, a polysaccharide comprised of glucose units
Cellulose