Cell Structure & Function Flashcards
The 6 primary tenants of cell theory are:
- All living organisms are made of cells.
- Cells are the basic unit of life.
- All cells arise from preexisting cells.
- Hereditary information is passed from cell to cell.
- All cells have the same basic chemiclal composition.
- Energy flow occurs within cells.
A set of defining principles that describes the characteristics of cells.
Cell Theory
Every cell shares at least 4 key components:
- Every cell has a plasma membrane that separates the cell’s interior environment from its exterior environment.
- Every cell has cytosol, a jelly-like fluid in which intracellular organelles are suspended. Organelles are specialized cellular structures that have specific functions within the cell. The space within the cell that contains cytosol is called cytoplasm.
- Every cell contains chromosomes that carry genes in the form of DNA.
- Every cell also contains ribosomes, which synthesize proteins.
A jelly-like fluid in which intracellular organelles are suspended.
Cytosol
Specialized cellular structures that have specific functions within the cell.
Organelles
The space within the cell that contains the cytosol.
Cytoplasm
Synthesize proteins.
Ribosomes
Simpler of the 2 cell types.
Lack internal division and organization (don’t have a nucleus or other membrane-bound organelles).
Unicellular.
2 major domains —> Archaea and Bacteria.
Prokaryotes
Structures of a prokaryotic cell include:
Pili
Flagellum
Cell Wall
Capsule
Plasma Membrane (Cell Membrane)
Cytoplasm
Ribosomes
Nucleoid
Hair-like appendages found on the cell surface of many bacteria.
Help bacteria adhere to extracellular surfaces.
Pili (Pilus)
Tail-like appendage (found on many bacterial cells) that enables movement.
Flagellum
A rigid layer of sugar-based molecules (surrounding most archaea and bacteria).
Provides structural support and protection to the cell.
Cell Wall
Sugar-containing layer associated with the virulence of bacteria.
Capsule
Microscopic membrane compose of fats and proteins that forms the external boundary between the cell and the outside world.
Composed of phospholipid bilayer —> Selectively permeable membrane that controls the flow of molecules, ions, and proteins into and out of the cell.
Helps protect the cell and helps it to maintain proper internal physiology.
Cell Membrane
Material within a cell enclosed by the cell membrane.
Cytoplasm
Sphere-shaped structures composed of RNA and protein that serve as the site of protein synthesis.
Suspended in the cytoplasm.
Ribosomes
The irregularly shaped region (within prokaryotes) that contains most of the genetic material of the cell —> Have a single circular chromosome.
Nucleoid
Much more complex than prokaryotic cells.
Most are multicellular, some are unicellular.
Contain a membrane-bound nucleus.
Contain membrane-bound organelles.
Contain multiple rod-shaped chromosomes where DNA is stored.
Eukaryotes
Every cell shares at least 4 key components:
Plasma Membrane
Cytosol
Chromosomes
Ribosomes
Phospholipid bilayers with embedded glycoproteins.
Semipermeable and function as an internal regulator (into and out of the cell).
Plasma Membranes
Cells that serve to absorb nutrients from food/blood have ______ along the plasma membrane.
Fingerlike projections that increase the cell’s surface area.
Microvilli
Space between the cell wall and the nucleus —> Fills the cell inside the cellular membrane and holds all cellular material in place.
Organelles are suspended in cytosol within the _______.
Cytoplasm
Specialized subunits that are often enclosed within their own lipid bilayers and are suspended in cytosol in the cytoplasm.
Organelles
Acts as the brain of the cell. —> Directing all cellular activities within other organelles, controlling DNA transcription/synthesis, determining which proteins will be made.
Cellular DNA stored within.
Has its own lipid bilayers that separates it from the cytoplasm.
Nucleus
Double membrane that surrounds the nucleus and offers an extra layer of protection.
Necessary to protect the nucleus (where the cell’s only copy of DNA is housed).
Allows for the passage of RNA, ions, and molecules between the nucleoplasm and cytoplasm.
Nuclear Envelope
Similar to cytoplasm but within the nucleus.
Semi-soft fluid that contains the nucleolus and chromatid.
Nucleoplasm
Contain DNA and in eukaryotes have a linear structure.
Chromosomes
To fit within the nucleus, proteins coil the DNA into smaller unites.
Chromatids
Even smaller region within the nucleus.
Produce ribosomes.
Nucleolus
Produced within the nucleolus.
Involved in DNA translation.
Once created, can leave the cell and can either float freely in the cytoplasm or stick to the sides of the nuclear envelope (endoplasmic reticulum.
Involved in protein production.
Composed of proteins and rRNA.
Ribosomes
Carries out cell tasks such as protein synthesis, transportation of proteins, molecules, and ions across membranes, and detoxification of poisons.
Nuclear Membrane & Endoplasmic Reticulum.
Endomembrane System
A plasma membrane that folds in on itself within the cell.
Composed of sacs and tubules.
2 types —> Rough & Smooth.
Endoplasmic Reticulum
Ribosomes studding its surface (bumpy appearance).
Ribosomes and ________ endoplasmic reticulum work together to produce proteins.
Rough Endoplasmic Reticulum
Fewer or NO ribosomes.
Manufactured lipids/fats.
Can also perform detoxification and stores calcium ions.
Smooth Endoplasmic Reticulum
Purpose is to finish producing protein and lipid products produced by the endoplasmic reticulum.
“Finishing touches” on early cellular products, packaging them into vesicles, and sending them to other regions of the cell.
Shipping and receiving center of the cell.
Similar in appearance to the endoplasmic reticulum but separated from the nucleus.
Golgi Apparatus
Endoplasmic reticulum is composed of sacs and tubules called…
Cisternae
Internal parts of the sacs/tubes within the endoplasmic reticulum is called…
Lumen
Wide arc on the Golgi apparatus.
“Front door” or receiving apparatus.
Cis Face (of the Golgi Apparatus)
Side of the Golgi apparatus where the finished proteins leave.
Trans Face (of the Golgi Apparatus)
The powerhouse of the cell. —> Cellular energy production cells.
Specialize in the generation of adenosine triphosphate (ATP) via cellular respiration.
Have their own ribosomes and DNA.
Mitochondria
An energy carrying molecule that is produced by cellular respiration.
Adenosine Triphosphate (ATP)
The process of making ATP from oxygen, glucose, and other nutrients and produce carbon dioxide as a waste product.
Cellular Respiration
Inner membrane layer folds of the mitochondria.
Cristae
Act as the cell’s recycling centers.
Filled with enzymes capable of breaking down proteins, polysaccharides, lipids, nucleic acids, and old organelles into products such as amino acids and peptides —> Autophagy.
Lysosomes
During this process, the damaged organelle or protein is encapsulated int e cell membrane and the lysosome attaches to its outside, the digestive enzymes then dismantle the material and ultimately send amino acids and other organic materials back to the cytoplasm for further use.
Useful scraps obtained through this breakdown process can be used for future cellular activities.
Autophagy
Similar to lysosomes in that they’re responsible for breaking down cellular products.
Primarily break down lipids/fats.
Peroxisomes
Membrane surrounded sacs located in the cytoplasm that have storage/transportation functions.
Can be bound to other membranes and move cellular materials (such as ribosomes or amino acids) around the cell.
Vesicles
Membrane surrounded sacs located in the cytoplasm that have storage/transportation functions.
Bigger than vesicles but the membrane never fuses to other membranes.
Act as a place for cells to store molecules before they’re released from the cell (exocytosis) or after they’re brought into the cell (endocytosis).
Vacuoles
Molecules released from the cell.
Exocytosis
Molecules brought into the cell.
Endocytosis
Plants, animals, protists, and fungi.
Can be multicellular or unicellular organisms (but more commonly multicellular).
Eukaryotes
Plant cells have but animal cells do not…
Chloroplasts
Amyloplasts
Cell Wall
Large(er) Vacuoles
Plants acquire their energy from sunlight and need this structure to convert solar power into sugars via photosynthesis.
Contain chlorophyll.
Chloroplasts
Contained within chloroplasts.
Absorbs sunlight.
Gives plants their green color.
Chlorophyll
A series of chemical reactions in which solar energy is converted into sugars.
Photosynthesis
Inner membrane of chloroplasts that is in the form of flattened, interconnected sacs.
Thylakoids
Thylakoids (within chloroplasts) can be stacked like coins. —> The stacks are called…
Grana
The space outside the grana (within the chloroplasts).
Contains the ribosomes and chloroplast DNA.
Stroma
Amyloplasts, chromoplasts, and chloroplasts are members of a family of related organelles called…
Plastids
Colorless and usually store starch in roots.
Store/synthesize starch, which can be converted into glucose, which then can be used for metabolic pathways and energy generation within the plant.
Amyloplasts
Store pigments that give fruits and vegetables their colors.
Chromoplasts
Only plant cells have.
0.1-1 micrometers thick and gives added stability and protection to the plant cell.
Cell Wall
Eukaryotic cells have these key defining features:
-Membrane-bound nucleus
-Membrane-bound organelles
-Multiple rod-shaped chromosomes
