A&P Ch 2: cells
Terms
undefined, object
copy deck
- List the order of cell creation from solar system to Eukaryotes
-
-solar system= 4.5 bil/y/a
-methane, water, and ammonia
-organic molecules
-prokaryote cells= 3 bya
-eukaryote cells= 1.5 bya - Growth
- increase in size
- Hypertrophy
- increase in size beyond normal (cell or organ)
- Atrophy
- decrease in size beyond normal
- Hyperplasia
- increase in number of cells in a tissue or organ
- Hypoplasia
- incomplete or defective development of a tissue or organ
- Aplasia
- failure of atissue or organ to develop
- Reproduction
- ability to produce more cells or organisms that are essentially the same as the original
- What is the difference between miosis and mitosis?
- Chromosome numbers.
- Absorption
- taking dissolved materials into the substance of the cell.
- What do all mammalian cells share in common?
-
-a cell membrane
-the cytoplasm
-the nucleus - What is the plasma membrane and AKA?
- The plasmalemma separates cells from their external environments.
- What is included in the cytoplasm?
- everything except the nucleus in a cell.
- What is cytoplasm and what is it composed of?
- It is a colloidal, jamlike protoplasm that is highly structured and composed of proteins, electrolytes, metabolites, a flexible cytoskeleton, and complex organelles.
- What is the purpose of organelles?
- To work collaboratively to carry out necessary metabolic functions.
- What are the percentages and parts of a cell membrane?
-
protein: 55%
phospholipids: 25%
cholesterol: 13%
miscellaneous lipids: 4%
carbohydrates: 3% - What is a lipid bilayer?
- Two layers of phospholipid molecules arranged with hydrophilic heads outside and hydrophobic fatty acid tails inside.
- What is the fluid mosaic?
- Suspended proteins in bilayer can move easily throughout the membrane constantly changing the pattern.
- What helps stabalize the membrane? How?
- Cholesterol molecules wedge themsleves between phospholipids and prevent lipids from aggregating which keeps the internal layer oily (this increases impermeability to water-soluble molecules).
- globular proteins
- Responsible for membranes special functions on or inside cell bilayer.
- What are globular proteins found in the bilayer called?
- Integral proteins. They span width of membrane and can form channels.
- What are globular proteins found on surface of bilayer called (internal or external bonding)?
- Peripheral proteins, sometimes act as enzymes to catalyze reactions and sometimes involved in changing cell shape.
- What is the glycocalyx?
- It is the "sugar coating" that covers surface of some cells. It probides improved cell to cell adhesion and represents intercellular recognition and for the interactions between cell and antibodies (or viruses).
- What makes up the glycocalyx?
- CAM's and membrane-receptors.
- What are CAM's?
- Cell Adhesion Molecules are sticky glycoproteins covering most mammilian cells for bonding to eachother. Also important in signaling circulation of cells, such as wbc's to areas of inflammation or infection.
- What are membrane receptors?
- Integral proteins and glycoproteins that act as binding sites on cell surfaces, play vital role in contact signaling, and chemical signaling.
- What is contact signaling?
- Cell to cell recognition, which is important in immune responses to infection.
- What is chemical signaling?
- The specific interaction of hormones and neurotransmitters to cell surfaces for the purpose of changing cell activity.
- What are ligands?
- Small molecules that bond to larger chemical groups or molecules and some then act as enzymes to activate or inactivate a particular cellular activity.
- What are flagella and cilia?
- Extensions of plasma membrane into extracellular space. They are composed of nine pairs of microtubules that encircle a central pair of microtubules. They originate from a pair of centrioles located at periphery of the cell (just under plasma membrane).
- Describe cilia.
- Occur in large numbers, about 10 micrometers long. They move synchronously to propel fluid, mucus, and debris across cellular surgaces. Known for functions in upper respiratory tract and oviduct.
- Describe flagella.
- Usually occur singly and attached to individual cells to propel them foward. Sperm is the only mammalian cell propelled by flagellum.
- What is cytosol?
- A viscous, semitransparent liquid composed of dissolved electrolytes, amino acids, and simple sugars.
- What gives cytosol its jellylike consistency?
- Suspended proteins give it a jellylike consistency and are important in metabolic activities of the cell.
- What is the cytoskeleton?
- It is a flexible, fibrous structure that changes with activities in cell. It gives support and shape to cell, enables movement, anchors organelles, and directs metabolic activity.
- What fibers make up the cytoskeleton?
-
-microtubules
-microfilaments
-intermediate fibers - What are microtubules?
- Thickest fiber in cytoskeleton, long and hollow tubes growing out from cell center to form cables for attaching mitochondria, lysosomes, and secretory granules.
- How do proteins function with the microtubules?
- They act as motors and move attached organelles along "tracks". They can be disassembled and reassembled for new pathways.
- What makes up microtubules? How do they attach and why is this important?
- Tubulins link together in a spiraled chain to give strength and flexibility to cilia and flagella and the cell.
- What are intermediate fibers?
- The toughest and most permanent (in cytoskeleton), ropelike fibers with high tensile strength to resist pulling forces. HAve different names for different cellular locations.
- What are microfilaments?
- Composed of contractile protein actin, and work with myosin to break apart cell and change its shape. Located near cell surgace. Smallest component of cytoskeleton.
- What is the largest organelle? What is it mostly known for?
- mitochondria are known for their ATP production (~95% of energy that fuels cells).
- What is responsible for ATP production that is found in mitochondria?
- cristae is the second (internal) membrane.
- What is fission and what does mitochondria use it for?
- The asexual division of an organism or cell into two indicidual daughter cells. Mitochondria do this when more energy is needed.
- What is the matrix
- The intercellular enzyme-rich liquid that contacts the critae.
- What is a ribosome?
- An organelle composed of ribonucleic acid located on the rough ER or suspended in cytoplasm, where protein synthesis takes place.
- What does smooth ER do?
- Active in the synthesis and storage of lipids (particularly phospholipids and steroids). In luver cells, it may also function to eliminate drugs and break down glycogen into glucose.
- What does rough ER do?
- It contains ribosomes which produce proteins that are moved into cisternae where they are modified before moving on to golgi apparatus.
- What is cisternae?
- Passageways for proteins to pass through (resercoir of water).
- What is the detailed golgi apparatus?
- Found near nuclues, composed of flattened cisternae. Sacs from ER fuse with membrane and pass proteins from stack to stack in g.a. Once modified as needed, they are packed into vesicles. Out they go into the cytosol.
- In a nutshell, what is the golgi apparatus?
- A modification, packaging, and distribution center for molecules destined for secretion or intracellular use.
- What are two other minor functions of the Golgi apparatus?
- It also functions in polysaccharide synthesis and in coupling of polysaccharides to proteins found on cell surface.
- What are lysosomes?
- An organelle that fights pathogens, repairs famaged tissues, and aids in intracellular digestion by engulfing materials with its membrane-bound vesicle bodies. It contains the digestive enzymes that help destroy microorganisms that have been phagocytized by the neutrophil.
- What is autolysis?
- The process of self-digestion. When cells die, lysosomes in them are triggered to burst open releasing caustic enzymes into cytosol.
- What are peroxisomes?
- Membranous sacs containing enzymes in the cell. Important for detoxification.
- What two major enzymes do peroxisomes contain?
-
-peroxidases
-catalases - What are peroxidases?
- They assist in converting free radicals to hydrogen peroxide.
- What are catalases?
- Reduce hydrogen peroxide into water.
- What are inclusions?
- Packaged units of metabolic products or substances the cell has engulfed. May be membrane bound or non-membrane bound such as lipid froplets and fat globules.
- What are centrioles?
- Paired hollow cylinders composed of microtubules. Help to organize spindle fibers during division, and also form bases of cilia and flagella (basal bodies).
- What are basal bodies?
- A pair of tubular structures. Each one is composed of nine microtubules surrounding another pair of microtubule. Basal bodies act as the bas eof cilia and flagella.
- What is anucleated? What is problematic with this?
-
Cells containing no nucleus, such as red blood cells.
Without one, cells can not divide, make protein, or enzymes, or repair themselces. They can only live 3-4 months! - Which animals contain nucleated red blood cells?
- birds and reptiles
- What are the four components of the nucleus?
-
1) nuclear envelope or membrane
2) nucleoplasm
3) chromatin
4) nucleoli - What is the nuclear envelope?
- TWO bilayers. The outer layer is continuous with ER and studded with ribosomes.
- What is the perinuclear cisternae?
- The space between the two layers of nuclear envelope.
- What is nucleoplasm?
- Similar to cytosol, it is a gel-like substance which fills the nucleus.
- What are histones?
- Globular protein found in cellular nucleus that connects with nucleic acid to form nucleoproteins. They form a complex with DNA in chromatin and act as regulators of gene activity.
- What is chromatin?
- A material that is composed of DNA and proteins and makes up chromosomes.
- What are genes?
- Specific sites on chromosomes that dictate heredity. Genes may control one specific phenotypic trait, whereas other traits require many genes for proper expression. Pairs of genes that control the same trait and are located on the same part of the chromosome are called alleles.
- chromosomes
- Threadlike accumulations of DNA in the nuclei of cells that are particularly visible during mitosis. The D??NA of chromosomes contains the genetic material of the cell. The number of chromosomes is constant within a given species.
- nucleoli
- Dark spherical objects contained within the nucleus that are the sites of ribosomal RNA synthesis. They are composed of DNA, RNA, and protein. Each cell's nucleus may have more than one nucleoli.
- What is interstitial fluid?
- extracellular fluid found in tissues (not lymphatic or blood vessels).
- concentration gradient
- The spectrum between the area of highest concentration and the area of lowest concentration.
- What is osmotic pressure?
- The force of water moving from one side ot th eother of the membrane.
- What happens if the extracellular fluid is hypotonic?
- Inside of cell is more concentrated and water rushes in causing swelling and possible bursting.
- What happens if the extracellular fluid is hypertonic?
- It is more concentrated than cell, so water leaves cell causing it to shrink.
- What is oncotic pressure?
- The difference between the osmotic pressure of blood and the osmotic pressure of interstitial fluid or lymph.
- What is a subcutaneous adema?
- Leaking of fluid into the tissue under the skin.
- What is ascites?
- When fluid leaks into the abdomen.
- What is filtration based on?
- Based on a pressure gradient which can force liquids through membrane if force is greater on one side than the other side.
- What is hydrostatic pressure?
- The force that pushes a liquid. (In blood, the heart generates this pressure).
- What transport processes don't require any energy?
-
-diffusion
-facilitated diffusion
-osmosis
-filtration - What transport processes require ATP?
-
-active transport
-Exocytosis
-Endocytosis
+phagocytosis
+pinocytosis
+receptor mediated - What is a symport system?
- All substances are moving in same direction in active transport.
- What is an antiport system?
- Substances being transported in opposite direction during active transport.
- How long can an ion pump go with one molecule of ATP?
- For every molecule of ATP, several cycles can occur.
- How does the sodium-potassium pump work?
- Two potassium in, three sodiums out.
- What is phagocytosis?
- eating of solid material
- What is pinocytosis?
- The engulfing of a liquid material through endocytosis (cell drinking).
- What is a phagosome?
- The vesicle formed by phagocytosis, which contains material to be digested.
- What is the macrophage?
- Phagocytic cells that can engulf relatively large cells or bits of debris. They may be fixed in place or they may travel around in the tissues. Mature macrophages may become more mobile during times of infection and inflammation.
- What is an amoeboid motion?
- Amoeba=like movement accomplished by the extension of pseudopodia to create a streaming movement of cytoplasm.
- What are pseudopods?
- "False Feet"; the temporary extension of the cells membrane and cytoplasm either for locomotion or engulfing nourishment.
- What is symport systems?
- Substances being transported in same direction during active transport.
- What is a macrophage?
- Phagocytic cells that can engulf relatively large cells or bits of debris. They may be fixed in place or they may travel around in the tissues. Mature macrophages may become more mobile during times of infection and inflammation.
- What is a coated pit?
- Parts fo the cell membrane that hace a hairlike coating necessary for endocytic functions. These portions of the cell membrane pinch off to form vesicles that aid in the intracellular transport of materials.
- What is excretion?
- Exocytosis of waste materials.
- What is secretion?
- Exocytosis of a useful product.
- What is a membrane potential?
- The difference in voltage that exists on either side of the cell membrane caused by the different concentrations of positive and negative charges.
- What is the resting membrane potential?
- The electrical charge of some cells at rest caused by differing concentrations of ions inside and outside of the cell membrane.
- What are somatic cells and how do they reproduce?
- All cells other then reproductive cells. They udergo mitosis.
- What are the two major stages of cellular life?
-
1) Interphase
2) Mitotic Phase - What are the divisions of Interphase?
- G1, S, and G2. *All continuous dispite clear divisions.
- What occurs in G1?
- Can last from a few minutes to several weeks or even years. Undergoes cellular growth where cell doubles in size and organelles. Centrioles preparing for cell division.
- What occurs in S phase?
- Synthetic phase has DNA replication, new histones are formed into chromatin forming identical replicas of genetic material.
- What occurs in G2 phase?
- Very brief, includes synthesis of enzymes and proteins needed for cell division and continued growth of the cell. Centrioles complete replication by end of phase.
- What is the mitotic phase of the cell?
- The period when the cell is actively dividing.
- What are the stages of the mitotic stage?
-
-prophase
-metaphase
-anaphase
-telophase
-cytokinesis - What happens in prophase?
- Chromatin strands coil and condense to form chromosomes, which are linked at the central kinetochore. A spindle apparatus takes form while the nuclear encelope disintegrates.
- What happens in metaphase?
- Chromosomes line up in the center of spindle. Centromere of each chromosome is attached to spindle fiber.
- What happens in Anaphase?
- Chromatids are pulled apart by spindle fibers to form a duplicate set of chromosomes. They cytoplasm constricts at the metaphyseal plate.
- What happens in Telophase?
- Chromatin begins to unravel at the poles of the cell, and a nuclear envelope appears. Cytokinesis marks the end of telophase.
- Contact inhibition
- Cells stop growth when they touch another cell.
- What is differentiation?
- The progressive acquisiton of individual characteristics by cells to enable them to perform different functions.
- What three factors play a role in the control of cell division?
-
1) contact inhibition
2) growth-inhibiting substances may be released from cells when numbers reach a certain point
3) A number of checkpoints are reached during cell division when the cell reassesses the division process (G1 and G2 phases).