Term
| What are all organisms made of? |
|
Definition
| All organisms are made up of cells. |
|
|
Term
| What is the simplest collection of matter that can live? |
|
Definition
|
|
Term
| Are cell structure and function correlated? |
|
Definition
| Yes, cell function and structure are correlated. |
|
|
Term
| How are all cells related? |
|
Definition
| All cells are related by their descent from earlier cells. |
|
|
Term
| What are some cons of electron microscopes rather than light microscopes? |
|
Definition
| e- microscopes kill cells and therefore not show important things that would be seen while cells are living. |
|
|
Term
| Which study uses microscopes to study cell structure? |
|
Definition
| cytology, the study of cell structure uses microscopes to examine cells. |
|
|
Term
| How does a light microscope work? |
|
Definition
| Visible light passes through a specimen and then through glass lenses which magnify the image |
|
|
Term
| What does the quality of an image depend on? |
|
Definition
| The quality of an image depends on magnification, resolution and contrast. |
|
|
Term
|
Definition
| the ratio of an object's image to its real size |
|
|
Term
|
Definition
| the measure of the clarity of the image, or the minimum distance of two distinguishable points (limited by the shortest wavelength of light) if this is too high or too low = cant see |
|
|
Term
|
Definition
| visible differences in parts of the cell |
|
|
Term
| How much can light microscopes magnify? |
|
Definition
| light microscopes can effectively magnify about 1,000 times the size of the actual specimen |
|
|
Term
| How is the contrast of cell components enhanced? |
|
Definition
| by staining or labeling cell components |
|
|
Term
| What is a limitation of the light microscope? |
|
Definition
| One limitation of the light microscope is that most subcellular structures, including organelles (membrane-enclosed compartments), are too small to be resolved by the light microscope. |
|
|
Term
| What are the two basic types of electron microscopes thats are used to study subcellular structures? |
|
Definition
1) Scanning electron microscopes
2) Transmission electron microscope |
|
|
Term
| What is a scanning electron microscope (SEM)? |
|
Definition
| SEMs focus a beam of electrons onto the surface of a specimen, providing images that look 3-D |
|
|
Term
| What is a Transmission electron microscope (TEMs)? |
|
Definition
| TEMs focuses a beam of electrons through a specimen. |
|
|
Term
| What are TEMs mainly used to study? |
|
Definition
| TEMs are mainly used to study the internal structure of cells. |
|
|
Term
| What does SEMs use on specimens when looking at them? |
|
Definition
| SEMs use a thin coat of gold on specimen. |
|
|
Term
| What does TEMs use on specimens when looking at them? |
|
Definition
| TEMs use specimens stained with atoms of heavy metal |
|
|
Term
| What is cell fractionation? |
|
Definition
| Cell fractionation takes cells apart and separates the major organelles from one another (based on size and density) |
|
|
Term
| What is the process of cell fractionation? |
|
Definition
| A centrifuge spins the test tubes and the pellet at the bottom becomes rich in certains substances depending on how long it is spun. |
|
|
Term
| What is the most powerful centrifuge used for cell fractionation? |
|
Definition
| The ultracentrifuge is the most powerful centrifuge used to fractionate cells into their component parts. |
|
|
Term
| Why is cell fractionation important to scientists? |
|
Definition
| Cell fractionation is important to scientists because it allows them to determine the functions of organelles. It's faster and they are able to do multiple cells at a time rather than one cell slowly at a time. |
|
|
Term
| How do biochemistry and cytology work together? |
|
Definition
| biochemistry and cytology help to correlate the cell function with it's structure which is important. |
|
|
Term
| What do faster spins in the centrifuge lead to? |
|
Definition
| Faster spins = smaller components in the pellet |
|
|
Term
| Fill in the blank: Eukaryotes have internal membranes that ___________________________. |
|
Definition
| Eukaryotes have internal membranes that compartmentalize their functions. |
|
|
Term
| Fill in the blank: The basic structural unit of every organism is __________________. |
|
Definition
| The basic structural unit of every organism is one of two types of cells: prokaryotes or eukaryotes. |
|
|
Term
| What domains of organisms consist of prokaryotic cells? |
|
Definition
| Only organisms of the domains of Bacteria and Archaea consist of prokaryotic cells. |
|
|
Term
| What domains of organisms consist of eukaryotic cells? |
|
Definition
| Protists, fungi, animals and plants all consist of eukaryotic cells. |
|
|
Term
| What are the basic features of all cells? |
|
Definition
The basic features of all cells are:
-chromosomes (carry genes)
-the plasma membrane
-semifluid (substance called cytosol)
-ribosomes (make proteins) |
|
|
Term
| What is the function of the plasma membrane? |
|
Definition
| The plasma membrane serves as a selective barrier around cells. It allows sufficient passage of oxygen, nutrients and waste to service the volume of every cell. |
|
|
Term
| What is the semifluid's function? |
|
Definition
| The substance called cytosol encloses the plasma membrane and is a part of the cytoplasm. |
|
|
Term
| What is the function of chromosomes? |
|
Definition
| The chromosomes carry genes and are in all cells. |
|
|
Term
| What's the function of ribosomes? |
|
Definition
| Ribosomes make proteins according to the directions that are given by the genes. |
|
|
Term
| Where are organelles and other "things" found. |
|
Definition
| Everything is found int he plasma membrane. |
|
|
Term
| What things characterize a prokaryotic (before nucleus/kernal) cell |
|
Definition
Prokaryotic cells have:
-no nucleus
-DNA in an unbound region called the nucleoid (open not bound) chromosomes found here
-no membrane bound organelles
-cytoplasm (inside cell) bound by the plasma membrane |
|
|
Term
| Do all cells have cell walls? |
|
Definition
| No, all cells don't have cell walls but most do. |
|
|
Term
| What traits help characterize a Eukaryotic cell? |
|
Definition
Eukaryotic cells have:
-membrane-bound organelles
-DNA in a nucleus that is bounded by a membranous nuclear envelope<--double membrane (most)
-cytoplasm in the region between the plasma membrane and the nucleus (most metabolic activities happen here)
-generally larger than prokaryotic cells |
|
|
Term
| Which are generally larger...prokaryotic cells or eukaryotic cells? |
|
Definition
| Eukaryotic cells are generally larger. |
|
|
Term
| Where is is the DNA in a nucleus bounded membrane found in eukaryotic cells? (thinks specific) |
|
Definition
| Found in chloroplast of plants and mitochondrion. |
|
|
Term
| What is the general structure of a biological membrane? |
|
Definition
| A double layer of phospholipids is the general structure of a biological membrane. |
|
|
Term
| Why are phospholipids able to anchor allowing their hydrophobic ends to stay unexposed? |
|
Definition
| The nonpolar amino acids allow them to anchor. |
|
|
Term
| What limits the size of cells? |
|
Definition
| The logistics on carrying out cellular metabolism limit cell size. |
|
|
Term
| What have a greater ratio of surface area to volume...a smaller or larger object? |
|
Definition
| A smaller object has a greater ratio of surface area to volume. |
|
|
Term
| What are some things that are only found in animal cells? |
|
Definition
Things only found in animal cells:
-lysosomes
-centrosomes w/ centrioles
-flagella (present in some plant sperm) |
|
|
Term
| What are some things that are only found in plant cells? |
|
Definition
Things found only plant cells:
-chloroplasts
-central vacuole
-cell wall
-plasmodesmata |
|
|
Term
| What is the function of the central vacuole in plants? |
|
Definition
| The central vacuole is common in larger plants. It stores, breaks down waste, hydrolysis of macromolecules, enlargement for growth (vital), and fills up when cells divide (helps cell divide) |
|
|
Term
| What is the purpose of the cell wall in plants? |
|
Definition
| The cell wall is the outer layer of the plant cell. It prefers hypotonic environments, maintains cell shape and protects the cell from damage. |
|
|
Term
| What is the cell wall of plants made up of? |
|
Definition
| The cell wall in plants is made up of protein, cellulose and other polysaccharides. |
|
|
Term
| What is the cell wall of plants made up of? |
|
Definition
| The cell wall in plants is made up of protein, cellulose and other polysaccharides. |
|
|
Term
| What is the process of photosynthesis? |
|
Definition
| photosynthesis is the conversion of sunlight energy into chemical energy stored in sugar molecules |
|
|
Term
| What factor does surface area increase by? (in terms of n) |
|
Definition
| Surface area increases by n^2 |
|
|
Term
| What factor does volume increase by? (in terms of n) |
|
Definition
|
|
Term
| Where is most of the DNA in a eukaryotic cell? |
|
Definition
| In a eukaryotic cell, most of the DNA is found in the nucleus. |
|
|
Term
| How do ribosomes use the information from the DNA? |
|
Definition
| Ribosomes use the information from dNA to make proteins. |
|
|
Term
| What is the function of the nucleus? |
|
Definition
The nucleus contains most of the cell
s genes and is usually the most conspicuous organelle. It also synthesizes mRNA. |
|
|
Term
| What is the function of the nuclear envelope? |
|
Definition
| The nuclear envelope encloses the bucleus, separating it from the cytoplasm. |
|
|
Term
| What is the function of the nuclear envelope? |
|
Definition
| The nuclear envelope encloses the bucleus, separating it from the cytoplasm. |
|
|
Term
| What is the nuclear membrane? |
|
Definition
| The nuclear membrane is a double membrane; each membrane consists of a lipid bilayer. |
|
|
Term
| What is the purpose of pores in relation to the nucleus? |
|
Definition
| Pores help regulate the entry and exit of molecules from the nucleus. They surround the nuclear envelope which surrounds the nucleus. |
|
|
Term
| What is the shape of the nucleus maintained by? |
|
Definition
| The shape of the nucleus is maintained by the nuclear lamina (which is composed of protein) It's an array of protein filaments. |
|
|
Term
|
Definition
| Chromatin are the genetic material form of DNA and protein. |
|
|
Term
| What is the function of chromosomes? |
|
Definition
| Chromosomes carry genetic information. |
|
|
Term
| What is the significance of the nucleolus? |
|
Definition
| The nucleolus is located within the nucleus and is the site of ribosomal RNA (rRNA) synthesis |
|
|
Term
| Where are the two locations that ribosomes carry out protein synthesis? |
|
Definition
| in the cytosol (free ribosomes) & on the outside of the E.R. reticulum/nuclear envelope (bound ribosomes) |
|
|
Term
| What are ribosomes composed of? |
|
Definition
| Ribosomes are particles made of ribosomal RNA and protein. |
|
|
Term
| Are ribosomes identical in structure? |
|
Definition
| Yes, therefore they can alternate their locations (cytosol (free) vs. nuclear envelope/outside of E.R. (bound) ) |
|
|
Term
| What holds the cells together? |
|
Definition
| A sticky coat called the extracellular matrix (looks like straws/tubes wrapped around various things) |
|
|
Term
| What components make up the cytoskeleton? |
|
Definition
| The cytoskeleton consists of micotubules, Intermediate Filament, and Microfilament |
|
|
Term
| What is the mitochondria made up of? |
|
Definition
| The mitochondria has an outer and membrane. with many foldings in both |
|
|
Term
| What is the mitochondria made up of? |
|
Definition
| The mitochondria has an outer and membrane. with many foldings in both |
|
|
Term
| What are the main ingredients of membranes? |
|
Definition
| Lipids and proteins are the main ingrediants fo membranes. |
|
|
Term
| What determines the function of a membrane? |
|
Definition
|
|
Term
| What may have been one of the earliest episodes of life? |
|
Definition
| The plasma membrane the barrier that encloses cellular organelles |
|
|
Term
| Why is cell to cell recognition important? |
|
Definition
| It serves as a defense for the immune systems. Rejects foreign cells. |
|
|
Term
| What does 'amphiphatic' mean? |
|
Definition
| It means that the molecules contains both hydrophobic and hydrophillic regions |
|
|
Term
| The difussion of a substance across a membrane is ___________. |
|
Definition
|
|
Term
| What are 6 major functions performed by plasma membrane proteins? |
|
Definition
1) attachement to cytoskeleton and extracellular matrix
2) transport: provide hydrophillic transports regions
3) enzymatic activity
4) signal transduction
5) cell to cell recognition
6) intercellular joining
|
|
|
Term
| The plasma membrane exhibits selective permeability , what does that mean? Why is it important? |
|
Definition
| The plasma membrane allows some subtances to cross it more easily than others. The ability of the cell to discriminate in its chemical exchanges with its environment is fundamental to life |
|
|
Term
| What are the most abundant lipids in most membranes |
|
Definition
|
|
Term
|
Definition
| it is an amphipathic molecule , meaning it has both a hydrophillic region and a hydrophobic region |
|
|
Term
| How are phospholipids and proteins arranged in the membranes of cells? |
|
Definition
| in the fluid mosaic model , the membrane is a fluid structure of various proteins embedded in or attached to a double layer of phospholipids |
|
|
Term
| Why are membrane proteins not very soluble in water? |
|
Definition
| Proteins are amphipathic. |
|
|
Term
| What is the primary function that holds membranes together? |
|
Definition
Hydrophobic interactions , which are much weaker than covalent bonds.
|
|
|
Term
| The temperature of which a membrane solidifies depends on what? |
|
Definition
| the types of lipids it is made of |
|
|
Term
| What are the two major populations of membrane proteins? |
|
Definition
-intergral proteins- penetrate they hydrophobic interior of the lipid bilayer
-peripheral proteins- are not embedded in the lipid bilayer , they are appendages loosely bound to the surface of the membrane |
|
|
Term
| How are glycolipids formed? |
|
Definition
| carbs are covalently bonded to lipids |
|
|
Term
| Define concentration gradient. |
|
Definition
| the region along which the density of a chemical substance increases or decreases |
|
|
Term
| What is diffusion across a membrane called? |
|
Definition
| Passive transport because no extra energy is needed. |
|
|
Term
|
Definition
| the diffusion of free water across a selectively permeable membrane , whether artificial or cellular |
|
|
Term
| the ability of a surrounding solution to cause a cell to gain or lose water is called what |
|
Definition
|
|
Term
|
Definition
| the control of solute concentrations and water balance. |
|
|
Term
| Channel proteins that transport ions are called what? |
|
Definition
|
|
Term
| Is facilitated diffusion considered passive transport? why or why not |
|
Definition
| yes because the solute is moving down its concentration gradient , which requires no energy |
|
|
Term
| what does active transport enable a cell to do? |
|
Definition
| to maintain internal concentrations of small solutes that differ from concentrations in its environment |
|
|
Term
| what is the function of a sodium-potassium pump? |
|
Definition
| it exchanges 3 Na+ for every 2 K+ across the plasma membrane of animal cells |
|
|
Term
| A transport protein that generates voltage across a membrane is called a what? |
|
Definition
|
|
Term
| What does a proton pump do? |
|
Definition
| Actively transports protons (H+) out of the cell |
|
|
Term
|
Definition
| when a cell secretes certain biological molecules by the fusion of vesicles with the plasma membrane |
|
|
Term
|
Definition
| he cell takes in biological molecules and particulate matter by forming new vesicles from the plasma membrane |
|
|
Term
| Define membrane potential. |
|
Definition
| is the voltage difference across a membrane |
|
|
Term
|
Definition
| the coupling of active transport of one substance with the diffusion of another against its concentration gradient |
|
|
Term
| What does active transport enable a cell to do? |
|
Definition
| Active transport enables internal concentrations of small solutes to be maintained that differently from usual concentration in it's enviroment |
|
|
Term
|
Definition
| A ligand is any molecule that binds to a receptor site of another molecule |
|
|
Term
| What type of molecules can cross the plasma membrane? |
|
Definition
| small, nonpolar, uncharged molecules |
|
|
Term
| Is diffusion spontaneous? |
|
Definition
| Yes, diffusion is spontaneous since there is no need for input energy |
|
|
Term
| Is facilitated diffusion considered passive transport? Why? |
|
Definition
| Facilitated diffusion is passive because it is moving down the concentration gradient which requires no energy |
|
|
Term
| Why aren't membrane proteins soluble in water? |
|
Definition
|
|
Term
|
Definition
| solute concentration inside and outside the cell are equal. no net movement of water |
|
|
Term
| What is facilitated difusion? |
|
Definition
| Diffusion that gets assistance in it's process by either carrier or channel proteins. It goes down the concentration gradient. Greatly speeds up difusion |
|
|
Term
|
Definition
| (shrinks) solution concentration is lower inside cell rather than outside. water rushes outward. |
|
|
Term
|
Definition
| difusion of free water across a selectively permeable membrane, whether artificial or cellular |
|
|
Term
| What does cholesterol do in the phospholipid bilayer? |
|
Definition
| decreases membrane fluidity by restraining lipid movement (prevents tight packing) |
|
|
Term
|
Definition
| control of solute concentrations and water balance |
|
|
Term
| What are the 3 types of cellular work powered by? |
|
Definition
|
|
Term
| What are the forms of energy? |
|
Definition
-Kinetic (motion)
-Heat
-Potential |
|
|
Term
| What does the binding of an activator do? |
|
Definition
| The binding of an activator stabilizes the active form of the enzyme |
|
|
Term
What does the binding of an inhibitor do?
|
|
Definition
| The binding of an inhibitor stabilizes the inactive form of the enzyme |
|
|
Term
| What are the most allosterically regulated enzymes made from? |
|
Definition
| Most allosterically regulated enzymes are made from polypeptide subunits. |
|
|
Term
|
Definition
| A coenzyme is an organic cofactor |
|
|
Term
|
Definition
| cooperativity is a form of allosteric regulation that can amplify enzyme activity. (1 substrate molecule primes an enzyme to act on additional substrate molecules more readily) |
|
|
Term
| What makes cooperativity a form of allosteric regulation? |
|
Definition
| Cooperativity is allosteric because bindingbuy a substrate to one active site affects catalysis in a different active site. |
|
|
Term
| What are the 3 types of work that a cell does. |
|
Definition
1) mechanical
2) chemical
3) transport |
|
|
Term
|
Definition
- 3 phosphate groups
- ribose
-adenine |
|
|
Term
| How do enzymes catalyze reactions? |
|
Definition
| Enzymes catalyze reactions by lowering the Activation of Energy barrier. |
|
|
Term
|
Definition
| pathway begins with reactants and ends with new products |
|
|
Term
| What is the first law of thermodynamics? |
|
Definition
| Matter is neither created nor destroyed. |
|
|
Term
|
Definition
| Bioengetics is the study of how organisms manage their energy sources |
|
|
Term
|
Definition
| Cofactors are nonprotein enzyme helpers that may be inorganic. |
|
|
Term
| What is an enzyme active site? |
|
Definition
| The region of the enzyme where the substrate binds |
|
|
Term
| What is feedback inhibition? |
|
Definition
| Feedback inhibition is the end of the end product of a metabolic pathway shuts down the pathway prevents a cell from wasting chemical resources by synthesizing more products than needed |
|
|
Term
|
Definition
|
|
Term
|
Definition
| the use of an exergonic process to drive and endergonic one |
|
|
Term
|
Definition
| the energy that can do work when temp and pressure are uniformed , only negative delta G is spontaneous |
|
|
Term
| What does the free energy change (delta G) tell us? |
|
Definition
| whether or not the reactions occurs spontaneously |
|
|
Term
|
Definition
| The reactant that an enzyme acts on is called the enzyme’s ______________. |
|
|
Term
| What is an anabolic pathway? |
|
Definition
| Anabolic pathways are the reactant that an enzyme acts on is called the enzyme’s |
|
|
Term
| What are the 4 ways that the active site can lower the energy activation barrier? |
|
Definition
1) orienting substrates correctly
2) straining substrate bonds
3) providing a favorable microenviroment
4) covalently bonding to the substrate |
|
|
Term
|
Definition
the totality of an organism chemical reactions , it is the emergent propoerty of life that arisese from interactions between molcules
|
|
|
Term
| What is a catabolic pathway? |
|
Definition
| release energy by breaking down complex molecules into smaller compounds ex. cellular respiration breaks down glucose in the presense fo oxygen |
|
|
Term
| What are Anabolic pathways? |
|
Definition
| consume energy to build complex molecules from simpler ones |
|
|
Term
|
Definition
| the study of how organisms manage thier energy sources |
|
|
Term
|
Definition
| the capacity to cause change. it exists in various forms |
|
|
Term
|
Definition
| the study of energy transformations |
|
|
Term
| What is the second law of thermodynamics? |
|
Definition
| every energy transfer or transformation increases entropy(disorder) of the universe |
|
|
Term
| What are spontaneous processes? |
|
Definition
| Processes that occur w/o energy input. They can happen quickly or slowly. |
|
|
Term
| What does equilibrium mean? |
|
Definition
| A state of maximum stability EX: death |
|
|
Term
| What is an exergonic reaction? |
|
Definition
| A rxn that proceeds with a net release of free energy and is spontaneous |
|
|
Term
| What is an energonic rxn? |
|
Definition
| Absorbs free energy from it's surroundings and is non spontaneous |
|
|
Term
| What forms when enzymes bind to substrates? |
|
Definition
| An enzyme-substrate complex forms with enzymes bind to the substrates. |
|
|
Term
| this fxns as the cells energy shuttle...what is it? |
|
Definition
| ATP fxns as the cells energy shuttle |
|
|
Term
| What does induced fit of a substrate bring about? |
|
Definition
| the induced fit of a substrate brings about the chemical groups of the active site into positions that enhance their ability to catalyze the rxn |
|
|
Term
|
Definition
-Ribose
-Adenine
-3 phosphate groups |
|
|
Term
| What are the 3 types of cellular work powered by? |
|
Definition
|
|
Term
|
Definition
| A chemical agent that speeds up a rxn without being consumed by the rxn |
|
|
Term
| What is activation energy? |
|
Definition
| Activation energy is the energy needed to start a chemical rxn |
|
|
Term
| What is an enzyme's active site? |
|
Definition
| An enzyme active site is the region on the enzyme where the substrate binds |
|
|
