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37 terms

MCAT "The Cell"

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Prokaryotes
Cell lacking a nuclear membrane and membrane-bound organelles, such as a bacterium.
Nucleoid
The region in prokaryotic cells where the chromosome is located.
Plasmids
Small rings of DNA found naturally in some bacterial cells in addition to the main bacterial chromosome.
Cytoskeleton
a microscopic network of actin filaments and microtubules in the cytoplasm of many living cells that gives the cell shape and coherence
Proteins that make up cytoskeleton
Actin filaments, intermediate filaments, microtubules
Phospholipid bilayer
a double layer of phospholipids that makes up plasma and organelle membranes
Hydrophilic
Region of phospholipid that faces interior and exterior of cell
Hydrophobic
Region of phospholipid bilayer that faces intramembrane space
Transport Proteins
A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane.
Cell adhesion molecules
Membrane proteins that allow cells to adhere to one another.
Nuclear membrane
thin structure that surrounds and protects the nucleus
Nuclear pores
structures in the nuclear envelope that allow passage of certain materials between the cell nucleus and the cytoplasm
Histones
protein molecules around which DNA is tightly coiled in chromatin
Nucleolus
The organelle where ribosomes are made, synthesized and partially assembled, located in the nucleus
Ribosome
small particle in the cell on which proteins are assembled; made of RNA and protein
Smooth Endoplasmic Reticulum
An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.
Rough Endoplasmic Reticulum
a region that is recognized by the grainy appearance of the ribosomes on their outer surface, where the cell's proteins are made
Golgi Apparatus
stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum
Exocytosis
process by which a cell releases large amounts of material
Lysosome
membrane-bound sac containing digestive enzymes that can break down proteins, nucleic acids, and polysaccharides
Autolysis
self-digestion occurring in plant and animal tissues, particularly after they have ceased to function properly
Cristae
An infolding of the inner membrane of a mitochondrion that houses the electron transport chain and the enzyme catalyzing the synthesis of ATP.
Mitochondrial Matrix
The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the Krebs cycle.
Intermembrane Space
the fluid filled space between the inner and outer mitochondrial membranes
Apoptosis
programmed cell death
Microbodies
Membrane-bound organelles specialized as containers for metabolic reactions. (Peroxisomes and Glyoxysomes)
Peroxisomes
Microbody responsible for the creation of hydrogen peroxide that is used to break down fats. Catalyzes detoxification reactions in liver.
Glyoxysomes
Important in germinating plants
Centrioles
One of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope; play a role in cell division.
Facilitated Diffusion
movement of specific molecules across cell membranes through protein channels
Active Transport
transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient
Endocytosis
process by which a cell takes material into the cell by infolding of the cell membrane
Pinocytosis
process by which certain cells can engulf and incorporate droplets of fluid
Phagocytosis
process in which phagocytes engulf and digest microorganisms and cellular debris
Capsid
A protein sheath that surrounds the nucleic acid core in a virus
Virion
a fully developed viral particle
Bacteriophages
viruses that infect bacteria