Cell structure/ types Flashcards
Mitochondria
“cellular power plants” because they generate most of the cell’s supply of adenosine triphosphate (ATP), used as a source of chemical energy via aerobic respiration. They take in O2, and Glucose and expel, CO2 , H2O, and ATP
ATP
Adenosine triphosphate: energy within cells for metabolism. It is produced by photophosphorylation and cellular respiration and used by enzymes and structural proteins in many cellular processes
Cytoplasm
is the region between the cell membrane and the nucleus. All the contents of the cells of prokaryotic organisms (which lack a cell nucleus) are contained within the cytoplasm
Lysosome
(Recycling Center) organelles that contain acid hydrolase enzymes to break down waste materials and cellular debris. They can be described as the stomach of the cell
Smooth Endoplasmic Reticulum
is involved in the synthesis of lipids, including oils, and fats (liver/muscle cells) and steroids (ovary/teste cells), and detoxification of drugs and poisons (liver cells)
Ribosome
(workbenches) Not an organelle (no membrane) synthesizes protein chains. It assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule. Ribosomes are divided into two subunits. The smaller subunit binds to the mRNA and then the roughER. (some remain ‘free’ and unattached)
Golgi Complex
(Distribution Center) receive Transport Vesicles and their modified proteins from RER. They are sorted and addressed, and some further modified. The proteins exit either out of cell, to cell membrane or into cytoplasm.
Transport Vesicle
(shuttles) membrane-lined spheres that transport proteins or molecules through cytosol via the microtubules.
Endomembrane System
group of membrane-lined organelles and transport vesicles in Eukaryotes
Aerobic Respiration
The breakdown of glucose to ATP using Oxygen within mitochondria. Oxygen (breathed in) + Glucose (eaten) = CO2 (exhaled) + Water + ATP (energy)
Free Ribosomes
Ribosomes that do not attach to the RER. They synthesize proteins using mRNA/tRNA for use within the cell (usually)
RNA (4 types)
mRNA- messenger RNA, transcribe the DNA code for a particular protein in nucleus, exit via pores, enter ribosome.
tRNA- transfer RNA, enter ribosome and match nucleotides with mRNA bonding their attached amino acids to form protein chain.
rRNA- ribosomalRNA used to make Ribosomes
microRNA- small RNA chains that halt translation by binding to the mRNA and cutting it in half
Nucleus (4 parts)
Nuclear Envelope: double membrane that confines the DNA and Nucleus
Nucleolus: Center of Nucleus that synthesizes rRNA
Nuclear Pores: Exits from Nucleus
DNA: cookbook of information for assembling proteins.
Flagella
Tail-like extensions that function for cell movement. (only animal flagella is sperm cell tail) They are extensions of the microtubules.
Cilia
Hair-like growths that move very rapidly for propelling cell, or moving material around cell. Common among single-celled organisms.
Cytoskeleton (3 sizes)
- Microfilaments: small fibers that reach out for movement or to capture prey. (pseudopodium)
- Intermediate Filaments: most stabilizing of cytoskeleton.
- Microtubules: largest, determine shape of cell. Act as monorails for organelles movement.
Cytosol
Gel-like liquid (mostly water) within the Cytoplasm. The matrix.
Organelle
Membrane bound, highly organized internal structure of a cell that performs a specific function. Specific to Eukaryotes
Prokaryotes Characteristics
Bacteria and Archaea DNA not enclosed (naked chromosomes) Much smaller than Eukaryotes single-celled Ribosomes Cell Wall Cell Membrane Flagella (sometimes)
Eukaryotes Characteristics
DNA enclosed within a Nucleus (membrane-lined) Much larger than Prokaryotes Multi-cellular (mostly) Compartmentalized Organelles (many types)
Virus
Alive/Not Alive debate
Largest Virus much smaller than smallest bacteria
cannot reproduce without using machinery of other cells
Nucleotides (3 parts)
- Phosphate Group the rails
- Sugar (deoxyribose)
- Nitrogen-containing base (4): Adenine(A) , Guanine(G), Cytosine(C), Thymine(T). the rungs
Nucleic Acids
DNA and RNA
Plant Cells have….. Animal Cells don’t
Cell Walls, Chloroplasts, Central Vacuole
Gap Junctions
Communication channels between adjacent cells in animals that open only as necessary.
Centriole
Cluster of microtubules that, during mitosis, pull DNA pairs apart to separate cells
channel protein
a type of pore in the cell membrane that channels molecules or ions across the membrane through the protein.
carrier protein
protein that selectively combine with ion or substance to help it move across the membrane. Think of a key fitting into a lock
fluid-mosaic model
a phospholipid bilayer has a fluid consistency similar to oil, allowing lipid molecules the freedom to move. Proteins embedded on the outside or within the bilayer form a mosaic pattern
glycolipids
are phopholipids that have attached carbohydrate (sugar) chainsglyco=sugar
glycoproteins
have attached carbohydrate (sugar) chainsglyco=sugar
selectively permeable
the fluid-mosaic membrane is selectively permeable because some small molecules can pass through the phospholipid bilayer but larger molecules cannot
Active Transport
Transport of a substance across a membrane that does not rely on the potential energy of a concentration gradient for the substance being transported and therefore requires and addititonal energy source (often ATP)
Amphipathic Molecule
A molecule containing both hydrophobic and hydrophilic regions.
Concentration Gradient
A difference in the concentration of a substance from one point to another, as for example, across a cell membrane.
Diffusion
The net movement of particles (atoms, molecules, or ions) from a region of higher concentration to a region of lower concentration, resulting from random motion.
Endocytosis
The active transport of substances into the cell by the formation of invaginated regions of the plasma membrane that pinch off and become cytoplasmic vesicles.
Exocytosis
The active transport of materials out of the cell by fusion of cytoplasmic vesicles with the plasma membrane.
Facilitated Diffusion
The passive transport of ions or molecules by a specific carrier protein in a membrane.
Gated Channel
Channel proteins that open or close based on the presence or absence of a physical or chemical stimulus.
Hypertonic Solution
A term referring to a solution having an osmotic pressure (or solute concentration) greater than that of the solution with which it is compared
Hypotonic Solution
A term referring to a solution having an osmotic pressure (or solute concentration) less than that of the solution with which it is compared.
Integral Protein
A protein that is tightly associated with the lipid bilayer of a biological membrane.
Isotonic Solutions
Solutions that have identical concentrations of solute molecules and hence the same osmotic pressure.
Ligand
A molecule that binds to a specific site in a receptor or other protein.
Osmosis
The net movement of water by diffusion through a selectively permeable membrane from a region of higher concentration of water to a region of lower concentration of water.
Passive Transport
The diffusion of a substance across a biological membrane.
Peripheral Protein
A protein associated with one of the surfaces of a biological membrane.
Phagocytosis
Literally, “cell eating”; a type of endocytosis by which certain cells engulf food particles, microorganisms, foreign matter, or other cells.
Pinocytosis
Cell drinking; a type of endocytosis by which cells engulf and absorb droplets of liquids.
Receptor-Mediated Endocytosis
A type of endocytosis in which extracellular molecules become bound to specific receptors on the cell surface and then enter the cytoplasm enclosed in vesicles.
Selective Permeability
Allowing some substances to cross more easily than others.
Sodium-Potassium Pump
Active transport system that transports sodium ions out of, and potassium ions into, cells.
Transport Protein
A protein that helps molecules or ions pass through lipid bilayer membranes.
Define a tissue.
- aggregation of similar cells and intervening extracellular matrix that serve specific function
- group of similar cells and surrounding extracellular matrix and extracellular fluid (also known as ‘intercellular’)
Name the four main tissue types.
- epithelia
- connective tissue
- muscles
- nervous tissue
Define organ.
- groups of tissues that are assembled into units that serve broad bodily functions
- ie: bones, skin
Cells perform these seven general functions (also list the associated cells):
- Movement (muscle cells)
- Conductivity (nerve cells)
- Metabolic absorption (kidney and intestinal cells)
- Secretion (mucous gland cells)
- Excretion (all cells)
- Respiration (all cells)
- Reproduction (most cells)
What are seven membrane proteins in the cytoplasmic membrane?
Channel Proteins
Enzyme Receptors Receptor Sites Identifier Proteins Carrier Proteins
Define: Metabolism
The sum of all physical chemical changes that occur in the body.
Define: anabolism
The building of larger substances from smaller substances, such as the building of proteins from amino acids.
Define: catabolism
The breakdown of larger molecules into smaller ones that the body can use for its own needs.
The three stages of cellular respiration:
Glycolysis Krebs (citric acid cycle, tricarboxylic acid cycle)Electron Transport System
Define: oxidation
Utilization of glucose by the cell
Cytoplasmic membrane
Contains cellular contents; regulates what enters and leaves the cell
Nucleus
Contains genetic information; control center of the cell