Midterm Study Guide Flashcards
What is the endoplasmic reticulum?
What are the two types of ER?
What are the functions of the two types of ER?
Folded network of lipid bi-layer
Rough ER - Dotted with Ribosomes, Manufactures fat-loving proteins
Smooth ER - No Ribosomes, Manufactures phospholipids, steroids, fatty acids and modifies proteins manufactured in the rough ER
What are the three types of cell junctions?
Which one is watertight?
Which type is connected to the cytoskeleton?
Which allows passage of cytosol, ions, and small molecules from one cell to another?
Tight Junctions: Water tight - hold liquid
Desmosomes: Hold cells together, hook into the cytoskeleton
Gap Junctions: Allow passage of Cytosol, Ions, and Small Molecules
What effect does concentration of substrate have on a reaction?
Low concentrations of either substrate or enzyme will result in relatively low rates of product turnover.
Increasing concentration of substrate will increase turnover until all enzymes are occupied with substrate.
In which direction does matter and energy move relative to its concentration gradient in diffusion?
Matter wants to move down concentration gradient from high concentration to low concentration until equilibrium is reached
What is fermentation? What are the two products of fermentation that we studied? Which type of fermentation are certain cells of the human body able to perform?
Where an organic molecule becomes the ultimate electron acceptor rather than molecular oxygen - the final pathway in fermentation is Glycolysis (not an electron transport chain, which is where it differs from Anaerobic) -
- Lactic Acid Fermentation - produces lactate as final product
- Alcoholic Fermentation - produces alcohol as final product
Muscle cells - perform lactic acid fermentation when they are oxygen deprived, resulting in lactate
What is cellular respiration?
Organisms release the stored energy from fueled sources in a complex series of reactions — this is known as cellular respiration
What is activation energy?
Energy needed to start a chemical reaction
What is a catalyst? What effect does a catalyst have on a reaction?
Catalyst, substance that:
- Lowers the activation energy of a reaction
- Speeds up a reaction (often by orders or magnitude)
- Is not changed by the reaction
What is active transport? What are the different types?
Primary Active Transport: transmembrane pump. Uses energy to move materials across a membrane Endocytosis: Vesicle Into a cell Exocytosis: Vesicle out of a cell
What is enzyme specificity?
Most (not all) enzymes are highly specific for their substrates
Usually only work on one substrate unless it’s putting two molecules together, “lock and key model”
What are the primary components of membranes?
MOSTLY lipid molecules (bilipid)
Some embedded protein
Small amount of carbohydrate
In what forms are carbohydrates found in membranes? What is their major function?
Glycolipids – one or more sugar molecules bonded to a lipid
Glycoproteins — one+ sugar molecules bonded to a protein
They serve as identity markers and recognition sites and identify other substances/foreign substances
What is a plasma membrane composed of?
Cytoplasm?
Plasma Membrane - Lipid Bi-layer + Some proteins and Carbs
Cytoplasm - Cytosol (mostly water) and Organelles and other suspended particles (anything between the plasma membrane and the nucleus)
What process do cells use to break down fatty acids? What happens to glycerol molecules from triglycerides?
Fatty acids undergo a process called β-oxidation to produce acetyl groups that are transported to the Krebs Cycle by coenzyme A
Glycerol can be converted into one of the intermediate molecules of glycolysis and is then metabolized in the process of glycolysis.
What are the three major functions of enzymes?
1. Building larger molecules (anabolic reactions – i.e. dehydration synthesis)
2. Breaking down larger molecules (catabolism – i.e. hydrolysis)
3. Rearranging atoms or groups of atoms within the molecule being acted upon – changing one isomer to another
What is meant by the term “amphipathic”?
Amphipathic (or Amphiphilic) contains regions that are both hydrophilic and hydrophobic so they can exist with both
What are the three states of matter in living systems? Which has the most kinetic energy? The least?
Solid - least kinetic energy, can’t move, only vibrate (potential energy)
Liquid
Gas - most kinetic energy, moving
(Plasma)
What are the nutritional categories into which organisms are classified?
Photoautotroph – green plants that photosynthesize, photosynthetic bacteria
Photoheterotroph – all examples are prokaryotes – can use light, but need organic molecules for carbon
Chemoautotroph – all examples are prokaryotes, bacterial that live in ocean around thermal vents – no light/blackness
Chemoheterotroph – fungi, all animals (including humans), some bacteria
What is a ligand?
Signaling molecule - binds to another molecule to communicate
Binding of a ligand to a receptor changes its shape or activity, allowing it to transmit a signal or directly produce a change inside of the cell
What is a nucleoid?
The non-membrane version of a Nucleus that consists of bundled genetic materal in a Prokaryotic cell
What are the parts of a cell?
- CYTOPLASM
- PLASMA MEMBRANE
- NUCLEUS
What is enzyme competition?
Enzymatic competition – occurs when more than one enzyme can act on a particular substrate
What are the three components of the cytoskeleton? What are the functions of each?
Microtubules - Act as highways, tiny little tube roads, for transport proteins, allow separation of chromosomes during cell division, and allow movement of cilia and flagella (Centrosome - center connection of the Microtubules)
Microfilaments - double helix made of protein actin, Provide support and movement
Intermediate Filaments - made of variety of proteins, Tough supporting frameworks, scaffold to hold organelles in place and help two cells attach to each other
What are the two general types of transport in biological systems? Which one requires the input of energy?
Passive Transport - utilizes natural gradients
Active Transport - Requires energy usually in the form of ATP
What is the structure of the nucleus?
- Nuclear Envelope (Membrane, with pores)
- Chromatin
- Nucleolus
What are 4 examples of functional groups that we studied in class?
-
Alcohol group
- -ol
-
Carboxylic Acid
- -oic Acid
-
Amine
- -amin
-
Thiol – rotten eggs
- -thiol
Levels of organization of living organisms and the definitions of each
Biosphere! – the world wide ecosystem, living / non-living components that we interact with like the atmosphere, soil, ocean
Ecosystem – all the living components that exist in a particular place, communities of organisms as well as the non living things (soil/water etc)
Community – group of living organisms that are all existing in the same place (includes different kinds/species) in one place
Population – group of all the same kind of one organism (species)
Organism – independent living unit
Organ System – group of organs that work together to perform a particular function
Organ – groups of tissues that operate to perform a common function
Tissue – collection of cells that operate together
Cell – smallest unit of life
- (Organelles) - microscopic organs in cells but NOT on its own living
- [Molecules] – specific arrangements of atoms
- [Atoms] – fundamental units of matter
5) The count of protons in an atom is better known as the what?
ATOMIC NUMBER
What is a scientific law?
What is a scientific theory?
Which is often associated with one or more mathematical formula(s)?
Scientific Law: A uniform or constant fact of nature that describes what happens in nature that is often associated with one or more mathematical formulae
Scientific Theory: A widely accepted, plausible, general statement about fundamental concepts in science that explain why things happen
Which of the four metabolic pathways that produce ATP requires oxygen?
Aerobic respiration
What are the two enzyme examples we studied in class? What do they do?
Superoxide Dismutase (SOD)
Catalase
Together they neutralize the superoxides in our cells to prevent them from reacting negatively (First SOD creates H2O2 + O2 then Catalase Breaks further into CO2 and H2O)
What is the addition of a phosphate to molecule known as?
Phophorylation
What is an isotope? What determines an isotope?
Same element with different atomic mass (same number of protons, different number of neutrons)
Neutron count determs the Isotope
What are the 5 types of reactions we studied in class?
1) Oxidation Reduction
2) Dehydration Synthesis
3) Hydrolysis
4) Phosphorylation
5) Acid-Base
What are the forms of passive transport?
- Simple Diffusion
- Water Channels
- Facilitated Diffusion
- Osmosis
A large molecule composed of many repeating subunits is a what? What are three categories of biological molecules that are examples?
POLYMERS (Poly – Many, MER – Parts)
- Carbohydrate
- Protein
- Nucleic Acid
What are the two categories of proteins associated with membranes?
Integral – embedded in lipid bilayer, doesn’t leave, also have hydrophobic/philic regions
Peripheral — attached to the surface of the membrane, can breakaway/leave
What are the 6 most common atoms in organic molecules?
Carbon Hydrogen Nitrogen Oxygen Phosphate Sulfur
What are endo- and exocytosis? What are the three types of endocytosis?
Endocytosis: Vesicle Into a cell
- Pinocytosis – invagination/formation of a pocket that is then pinched off into a vesicle inside the cell (pino – “to drink”)
- Phagocytosis – a cell extends its membrane to engulf a solid particle creating a structure called a phagosome
- Receptor-mediated endocytosis – similar to pinocytosis but requires activation of receptors on the cell membrane by ligands – signal molecule (ligate/ligature – bind to)
Exocytosis: Vesicle out of a cell
Know that mitochondria are theorized to have once been separate prokaryotic organisms that were incorporated into eukaryotic cells in a process called endosymbiosis
ENDOSYMBIOSIS. BINARY FISSION. OWN DNA. (mtDNA and their own Ribosomes)
What is the name of a reaction involving two molecules being joined with the removal of a water molecule? What is the opposite reaction called?
Removal - Dehydration Synthesis
Opposite - Breaking down - Hydrolysis
What molecule is the universal currency of energy in living organisms?
ATP
Atoms tend to react to gain as stable number of how many electrons in their outermost shell? What is this rule known as? What is the exception to this rule?
ATOMS TRY TO GET 8 ELECTRONS - OCTET RULE
EXCEPTION: HYDROGEN - HELIUM IS CLOSEST AT 2 ELECTRONS IN VALENCE SHELL
NOT STUDIED: BORON and ALUMINUM - 6 VALENCE but not a thing to know
What are ribosomes? Where are they located? What is their function? What are they composed of?
NO MEMBRANE organelles
ALL CELLS HAVE RIBOSOMES
- Located on the ER
- On the Nucleus
- In Mitochondria
- Free floating in the Cytosol
Manufacture proteins from mRNA and Amino acids (Translation)
Composed of: 2 Ribosomal subunits rRNA and Protein
The portion of an organic molecule that determines its chemistry is known as a what?
FUNCTIONAL GROUP
How many bonds does a carbon atom form?
Tetravalent - Forms 4 Covalent Bonds
What are the four ways that organisms produce energy?
- Glycolysis
- Fermentation
- Anaerobic Respiration (only one we can’t do?)
- Aerobic Respiration
What are proteins? What are the main categories of proteins?
Polymers of amino acids
i. Structural Proteins (Collagen)
ii. Regulator Proteins
iii. Carrier Proteins
What is a nonscience? How is it different from a science? What are some examples?
- Disciplines that cannot be tested by experimentation
- Do not show a significantly high degree of cause-and-effect
- Have poor predictive value
- Cannot make use of the scientific method
SCIENCE REQUIRES QUESTIONS THAT HAVE A FACTUAL BASIS
What is the Golgi apparatus? What is its function?
Flattened, stacked, membranous organelle
- Receives
- Stores
- Modifies
- Packages proteins from the ER
Groups of orbitals are known as? What is the outermost level called?
GROUPS OF ORBITALS ARE SHELLS
OUTERMOST SHELL IS A VALENCE SHELL
What is biology?
A branch of knowledge that deals with living organisms and vital processes