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244 Cards in this Set
- Front
- Back
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Critical Thinking
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Means judging information before accepting it. When you do this, you get more out of the material such as underlying assumptions by evaluating statements and thinking of alternatives
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Evidence Based Thinking (5)
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1) Be able to clearly state your view on a subject
2) Be aware of the evidence that led you to this view 3) Ask yourself is there alternate ways to interpret this evidence 4) Thinking about the kind of information that might make you reconsider your view *If there is nothing that can change or persuade you to alter your view, recognize that you are NOT being objective about this subject |
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Science and the supernatural
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Does not assume or deny that supernatural phenomena occur.
Does not address it |
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Scientists certain standard
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Explanations must be testable in the natural world in ways that others can repeat
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How do you do critical thinking? (6)
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1) Be aware of what you intend to learn from the new info
2) Be conscious of bias or underlying agendas 3) consider your own bias 4) question authority figures 5) decide whether ideas are based on opinion or evidence 6) then decide whether to accept or reject the information or postpone judgment |
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Science (3)
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systematic study of nature
it limits science to waht we can observe objective not subjective |
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Discovery Science
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Discovery of new information on what we can record, measure or observe
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Examples of Discovery science
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animal behavior, descriptive anatomy (the knee bone is attached to leg bone)
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Inductive reasoning (Descriptive reasoning)
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Reasoning from specific observations to general theories
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Biology is the study of...?
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life
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On average how many questions a day does a 4 year old ask?
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400 questions...
ask why in biology! |
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Hypothesis Driven Science
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Also know as the scientific method
It is discovery beginning witha specific question. It uses controlled experiments to test a tentative answer. |
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The steps of the scientific method (7)
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1) observations
2) question 3) hypothesis 4) prediction 5) perform a controlled experiment 6) results 7) conclusion/report |
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Where does the if then process occur?
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Prediction step.
"IF the HYPOTHESIS is not wrong THEN PREDICTION" |
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Scientific theory: 3 qualifications
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1) a hypothesis holds up after years of tests
2) Helpful in making predictions about other phenomena 3) Its predictive power has been test many times |
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Scientists prefer to say...
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it supports or does not support the hypothesis
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How close to the truth do scientists get?
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a "theory"
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Variable
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some characteristic or an event that differs among individuals or systems and that may change over time.
experimenters measure and manipulate variables |
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How do scientists simplify observations?
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testing only one variable
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Sampling error
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the difference between results from a subset and results from the whole
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Ways to reduce sampling error (2)
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-have a large sample
-repeat the experiment |
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Deductive Reasoning
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reasoning from general theories to account for specific experimental results
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What were the problems/limitations of the MMR study at wakefield?
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1) sample was very small (12 children)
2) No healthly control group 3) they did not identify the time period during which the cases were identified |
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What is an organic compound?
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Known as the molecules of life. They contain one carbon and at least one hydrogen atom.
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Functional groups
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Certain atoms or clusters of atoms covalently bonded to carbon.
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What do living things consist mainly of?
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hydrogen,oxygen and carbon
*You have H20 and carbond makes more than half of whats life |
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Carbon can bond with up to how many atoms?
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Four
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Organic compounds consist of? (Structure)
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have a backbone of carbon atoms to which functional groups attach to
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Common functional groups are?
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Hydroxyl, Methyl, Carbonyl, Carboxul, Amino, Phosphate
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Metabolism
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Activities by which cells acquire and use energy
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How do they carry out metabolism?
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Cells construct, rearrange, and split organic compounds
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Enzymes
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Proteins that make reactions proceed faster than they would on their own
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Name the main metabolic reactions
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1) condensation
2) hydrolysis 3) electron transfer 4) functonal group transfer 5) rearrangement |
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Condensation
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Two molecules convalently bond into a larger molecule.
Water is usually forms as a product due to enzymes removing an -OH group from 1 of the molecules and a H from another small molecule. |
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Cleavage
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A large molecule splits into 2 smaller ones as by hydrolysis
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Hydrolysis
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Reverse of condensation.
By adding water, enzymes break a bond and attach a -OH group to one of the exposed bonding sites and a H atom to the other. H and OH are taken from a water molecule. |
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Electron transfer
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Metabolic reaction where one or more electrons taken from one molecule are donated to another molecule
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Functional group transfer
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Metabolic reaction where one molecule gives up a functional group entirely, and a difference molecule immediately accepts it.
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Rearrangement
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Metabolic reaction where juggling of internal bonds converts one type of organic compound to another
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Monomers
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small organic molecules that are used as sources of energy or as subunits to build larger molecules
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Polymers
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Chains of 3 to millions of monomers.
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What happens when polymers are broken down?
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They are broken down and released monomers may be used for energy or reenter cellular pools
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Molecular Bonds (2)
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Ionic bonds
covalent bonds |
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Ionic bonds
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electrons are not shared
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Covalent bonds
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shares electrons (1, 2, 3 pairs)
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Which are stronger ionic or covalent bonds?
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covalent are very strong and are often stronger than ionic
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Polar covalent
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electrons are not shared equally
so there are "poles" which are slightly negative and slightly positive ends |
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Nonpolar covalent (2)
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electrons are shared equally
they are hydrophobic |
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Hydrogen bonds
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attraction between two polar molecules. There is a slightly positive and slightly negative atom and they attract. between hydrogen atoms
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3 properties of hydrogen bonds
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1) individually are weak, collectively strong
2) can hold 3 dimensional shape of a molecule 3) easily broken or disrupted |
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Four major macromolecules in the cell
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1) carbohydrates
2) proteins 3) lipids 4) nucleic acids (DNA & RNA) |
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What link monomers together?
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condensation aka deydration synthesis
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What breaks polymers into monomers?
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hydrolysis
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3 types of carbohydrates`
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1) monosaccharides
2) oligosaccharides 3) polysaccharides |
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Carbohydrates (3)
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- Organic molecule that consists of carbon, hydrogen and oxygen in a 1:2:1 ratio
-Sugars and other carbonhydrates are the most abundant of all biological molecules -They can be stored, used for structural materials or as sources of energy |
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Monosaccharides (simple sugers)
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Monomers
Chemical formula: CH20 ex: glucose, sucrose, maltose |
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Glucose (chem formula and function)
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C6H12O6
main fuel for our cells |
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Fructose (chem formula and location)
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C6H12O6
corn syrup |
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Galactose
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C6H12O6
in milk |
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Disaccharides/Oligosaccharides
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short chain carbohydrates
2 monosaccharides joined together ex: lactose, sucrose, and maltose |
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Lactose
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galactose and glucose
milk sugar |
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Sucrose
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fructose and glucose
table sugar |
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Maltose
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germinating cereals like barley glucose and glucose
malt sugar |
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Polysaccharides (complex carbohydrates)
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Straight or branched chains of many sugar monomers (100s or 1000s)
There can be one or many types of monomers in a polysaccharides |
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Most common polysaccharides?
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starch, cellulose, glycogen and chitin
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Starch (4)
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glucose polymer
staircase does not dissolve easily in water (Resists hydrolysis) glucose storage in plants |
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Cellulose (5)
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glucose polymer
tightly bonded chains resists hydrolysis structural molecule for plants found in cell walls and in tall stems resisting mechanical stress aka fiber |
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Glycogen (2)
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Glucose polymer
Glucose storage for animals found in abundance in muscles and liver cells |
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Chitin
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glucose polymer
has nitrogen containing groups attached structural molecule for some animals it strengthens the hard parts of many animals such as a cuticle of crabs, insects and ticks |
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Lipids
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Fatty, oily, or waxy organic compounds that are insoluble in water
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Fatty acids
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simple, organic compounds with a carboxyl group that is joined to a backbone of four to 36 carbon atoms.
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What are the "essential fatty acids"?
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omega 3 and omega 6
and they can only come from your food |
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What are the 4 kinds of lipids?
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fats, phospholipids, waxes, cholesterol and other sterols
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Structure of fats
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1, 2, or 3 fatty acids that dangle like tails from glycerol (small alcohol)
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Triglycercides
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energy storage for plants and animals
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Which fatty acid chains some double bonds and do not pack tightly?
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unsaturated fats
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Which fats are liquid at room temperature?
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unsaturated fats
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What are the "good" fats?
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unsaturated fats
ex. vegatable oils |
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Which fatty acid chains lack double bonds and are packed tightly together?
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saturated fats
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Which fats are solid at room temperature?
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saturated fats
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What are the "bad" fats?
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saturated fats
ex: butter |
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Trans fats and hydrogenation
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-made when manufacturers add hydrogen to vegetable oil to increase shelf life and falvor stability of foods containing these fats.
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What does trans fat increase?
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LDL (low density lipoprotein) also known as bad cholesterol
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What does trans fat decrease?
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high density lipoprotein
also known as good cholesterol |
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Phospholipids are a major componment in what?
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cell membranes
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Monomers of phospholipids
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phosphate head (hydrophilic) and two fatty acid tails(hydrophobic)
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Cell membranes have how many phospholipid layers?
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2
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Hydrophobic tails + hydrophilic heads =
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amphiphilic
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Function of waxes (3)
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1) restrict water loss (cuticles)
2) protect (keep parasites out) 3) lubricate, soften (Skin and hair) |
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Structure of waxes
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1 long fatty acid + alcohol or carbon ring
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Important property of waxes
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more hydrophobic than triglycerides
they are firm water repellent lipids |
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Steroids structure
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4 carbon rings and no fatty acids
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Examples of steroids
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hormones, cholesterol
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Most common type of sterol in eukaryotic cell membranes?
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cholesterol
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What is a precursor to making many other important steroids?
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cholesterol
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Advantage of lipids to health
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They allow your cells to make important molecules
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Disadvantage of lipids to health
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Too many can lead to artery disease called atherosclerosis
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Bad cholesterol (LDL) should be less than? Why?
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130 mg/dl
excess can leads to plaques |
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Good cholesterol (HDL) should be higher than? Why?
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40 mg/dl
to help prevent heart disease by carrying bad cholesterol away from arteries |
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Triglycerides should be less than?
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150 mg/dl
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Amino acids
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Monomers (building blocks) for proteins. It is a amino group, carboxyl group and a R group.
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How many different types of amino acids are there?
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20
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How many amino acids are "essential" that must come from our diet?
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9
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How many different chemical properties do amino acids have?
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Many!
can range from hydrophobic, hydrophilic, charged, large,small etc. |
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Proteins
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organic compound composed of one or more chains of amino acids
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What determines the order of the 20 amino acids?
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DNA instructions
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Peptide bond
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joins the amino group of one or more amino acid with the carboxyl group of another
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Polypeptide chain
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Consists of several amino acids
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Protein primary structure
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Unique sequence of amino acids held together by strong peptide (covalent) bonds
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Secondary structure
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Held together by weak hydrogen bonds between the amino group of one amino acid and the carboxyl group of another amino acid.
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Two major types of secondary structure
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alpha helix and beta pleated sheet
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Tertiary structure
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Held together by unique interactions between R groups, many are hydrogen bonds. This is where the domain is organized as a structurally stable unit such as clusters, pockets and barrels
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Domain
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part of the protein that is organized as a structurally stable unit
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Quaternary structure
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Consist of two more polypeptide chains bound together
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Fibrous proteins consist most of?
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entirely alpha helixes
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Globular proteins consist of?
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alpha helixes and beta pleated sheets
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An example of a slight change in structure of a protein
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sick cell anemia
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Denature
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secondary, tertiary and quaternary structure will unravel
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What do detergents do?
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disrupt the hydrogen bonds and other interactions that maintain a proteins shape which can affect the function
can be heat |
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Prions
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a misfolded protein that is resistant to normal cellular degradation int he brain cells and has the ability to convert folding protein into this misfolded type
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What happens when a cell becomes clogged with this misfolded protein?
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leads to cell death
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What are examples of t his infectious protein- prion?
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mad cow disease, CJD
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List proteins diverse functions (6)
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1. structural (lips, collagen)
2. contractile (heart) 3. storage (egg) 4. defensive 5. transport, signaling (cell communication) 6. enzymes (catalyze reactions- lactase) |
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DNA consists of:
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deoxyribose (5 carbon surgar with one oxygen attached)
phosphate group (negative charge) one of the four nitrogenous bases |
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ribose
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two oxygen atoms attached to the ring
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Double helix structure
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2 interacting polynucleotides held together by hydrogen bonds
A=T G=C |
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RNA consists of:
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ribose (5 carbon sugar with two oxygen atoms attached to the ring)
phosphate group 1 of the 4 nitrogen bases (A,U,G,C) |
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Single stranded? Double stranded?
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single: RNA
double: DNA |
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ATP structure
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nucleotide
3 phosphate groups attached to a sugar |
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ATP function
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Transfers the outermost phosphate to many other molecules and primes them to react...it is vital for metabolism
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Coenzymes function
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moves electrons and hydrogen from one reaction site to another
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Examples of coenzymes
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NAD+ and FAD
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What nitrogen base does RNA have instead of a DNA base?
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It has uracil instead of thymine
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Adenine binds to what base?
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thymine
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Guanine binds to what base?
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cytosine
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define cell
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smallest unit that shows the properties of life, which means it has a capacity for metabolism, homeostasis, growth and reproduction
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All cells have what 3 features in common?
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Plasma membrane
DNA containing region Cytoplasm |
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Which is smaller prokaryote or eukaryote?
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prokaryote
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define Lipid bilayer
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double layer of lipids organized so that their hydrophobic tails are sandwiched between their hydrophilic heads
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What are embedded in a bilayer or attached to its surface that carry out membrane functions?
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proteins
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Surface to volume ratio
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The ratio is that an objects volume object volumes increases with the cube of its diameter and the objects surface area increases only with a square
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Which increases faster in a cell, volume or surface area?
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volume
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What is the problem with a large volume?
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trouble moving substances through its cytoplasm and nutrients would be distributed fast enough
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Cell shape that provides advantage is?
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long, thing and have folds to increase SA
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Two kinds of cells
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eukaryotes and prokaryotes
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Cell Theory
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1)Every organism consists of one or more cells
2)The cell is the smallest unit having the properties of life 3)Life arises from the growth and division of single cells |
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Fluid mosaic model
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describes a cell membrane of mixed composition
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Fluid mosaic model: Fluid
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all of these molecules move laterally
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Fluid mosaic model: mosaic
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mixed composition of phospholipids, sterioids, various proteins, cholesterol, etc
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The functions of the proteins in the lipid bilayer?
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signaling, transport, enzymes, etc
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True/false: All plasma membranes incorporate many kinds of proteins.
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true
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Transporter proteins
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span all cell membranes, they help solutes move across the bilayer, some let some flow through and others pump them across
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Receptor proteins
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respond to signals or stimuli from the outside and trigger changes in cell activities. Different cells have different receptors
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Adhension proteins
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help cells migrate to certain regions and stay there
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Recognition proteins
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identify a cell as self or nonself
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Communication proteins
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form channels that allow substances or signals to flow freely across the plasma membrane of adjacent cells.
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Where are communication proteins often abundant?
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heart muscle and other tissues where cells interact fast
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Passive transporters
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let pass
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Active transporters
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pump across
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Components of prokaryotic cell from the outside to the inside
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flagella, pili, capsule, cell wall, plasma membrane, chromosome, ribosome
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Prokaryotes: single or multi cell?
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single cell
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Prokayotes are grouped into what domains?
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bacteria and archea
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Which domain resembles eukaryotes?
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archea
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What gives the prokaryote cell its shape?
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protein filaments under the plasma membrane
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Cell Wall
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rigid support for the cell, helps regulate transport in and out of the cell
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Is the cell wall in a prokaryote and a plant the same?
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NO
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Capsule
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Jelly like layer consists of sticky polysaccharides that help cells attach to surfaces and protects them from predators and toxins
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Flagella
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rapid movement
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Prokaryotic flagella movements?
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like a propeller
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Eukaryotic flagella movements?
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like a bend and whip
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Pili
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protect from the surface of bacteria and help cells cling and move across surfaces
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What do "Sex" pilus do?
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They attach to another bacterium and shortens. The attached cell is reeled in and genetic material is transferred into it.
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Prokaryote chromosome
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region where a single,circular DNA molecule in the cytoplasm
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Prokaryote ribosome
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polypeptide factories in the cytoplasm
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Plasmids
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smaller circles of DNA that carry a few genes that have an advantages such as antibiotic resistance
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Plasma membrane of archeans and bacteria is selectivly permeable?
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yes
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Nucleoid
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irregular shaped region where DNA is located but not enclosed into a membrane
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Which type of cell shows the mmost metabolic diversity?
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prokaryotic cells
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Biolfilms
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single cell organisms live in a shared mass of slime. contains multiple species
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Biolfilm slime is made by what?
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secreted layer of polysaccharides and glycoproteins
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Nucleus
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protecting and controlling access to DNA
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Endoplasmic reticulum (ER)
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routing, modifying new polypeptide chains, synthesizing lipids, etc
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Golgi body
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modifying new polypeptide chains, sorting, shipping proteins and lipids
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Vesicles
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Transporting, storing or digesting substances in a cell, other functions
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Mitochondiran
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Making ATP by glucose breakdown
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Chlorplast
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making sugars in plants, some protists
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Ribosomes
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assembling polypeptide chains
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Cytoskeleton
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contributing to cell shape, internal organization and movement
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Components of eukaryotic cells with membranes (6)
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nucleus, ER, Golgi body, vesicles, mitochondrian, chlorplast
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Components of eukaryotic cells without membranes
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ribosomes
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Nuclear envelope
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pore riddled double membrane that controls which substances enter and leave the nucleus
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How many lipid bilayers does the nuclear envelope?
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2
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What does the outer membrane of the nuclear membrane do?
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merges with the membrane of the ER
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Nucleoplasm
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semifluid interior matrix portion of the nucleus
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Nucleolus
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Where ribosome subunits are assembled from proteins and RNA. These subunits formed pass through the pores of the nucleolus where they can participate in protein synthesis.
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The organelles of the Endomembrane System (4)
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endoplasmic reticular
golgi bodies vesicles that bud from the ER and golgi vesicles that bud from the plasma membrane |
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Structure of endomembrane reticular
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continuous compartment that folds over and over into flattened sacs and tubes
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Rough ER
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has ribosomes attached to the outer surface. This is where polypeptide chains enter and where they are modified or they become part of the ER membrane
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What type of cells have alot of rough ER?
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cells that store and secrete proteins
such as the pancreas: make and secrete enzymes for digestion |
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Smooth Er (5)
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does not have ribosomes.
It makes lipids for cell membranes Has roles in carbohydrate and fatty acid breakdown Roles in detoxifying some drugs/poisions One type stores calcium ions and role in contraction |
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Endocytic pathway for a protein
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Patches of plasma membrane sink inward, forming endocytic vesicle that move their contents into the cytoplasm
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Exocytic pathway for a protein
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1) dna makes instructions for proteins
2) RNA messengers make polypeptide chains that either go to the cytoplasm to be used or to the rough ER 3) Rough ER takes the protein through its channels for modification 4) The protein then will either be inserted into an organelle membrane or secreted from the cell 5) Some proteins then go to the smooth ER to be used for membranes or enzymes 6) The golgi then receives, repackages the protein into a vesicle 7) the vesicle then transport substances outside the cell 8) exocytic vesicle fuses with the plasma membrane and their contents are released outside the cell |
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Lysosomes
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vesicles that bud from golgi bodies and take part in intracellular digestion. They have enzymes that break down carbohydrates, proteins, nucleic acids, and some lipids. Also destroy bacteria or any unwanted cell parts
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Vacuoles
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small vesicles fuse into a larger sac
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Central vacuole
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In a plant cell, where amino acids, sugars, toxins and ions accumlate.
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What organelle is responsible for the leaves and the stems firm?
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central vacuole fluid pressure
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Peroxisomes (4)
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-Found in animals and plants
-Form and divide on their own -Contain enzymes that digest fatty acids and amino acids -Break down hydrogen perioxide and convert it |
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What cells contain alot of mitochondira?
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liver, heart, skeletal muscles, other tissues that demand alot of energy
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How many membranes does the mitochondria have?
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two membranes, one is highly folded inside the other
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Where did mitochondria believe to come from?
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from bacteria that took up permanent residence in a host cell
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What does the inner membrane function in the mitochondria?
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allows ions to flow across the inner membrane which drive formation of ATP
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Which cells contain chloroplasts?
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photosynthetic eukaryotic cells
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What happens inside chloroplasts?
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Sunlight energy drives photosynthesis where ATP and NADPH are formed and used to produce glucose from carbon dioxide
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Stroma
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semifluid interior of the chloroplast enclosed by two outer membranes
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How many membranes does the choloroplast have?
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two outer membranes
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Thylakoid membrane
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Folded up int he stroma, organized in channels or stacked discs. There are chemicals in the thylakoid membrane that trap light energy to make ATP
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Where do chloroplasts believe to evolved from?
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Bacteria that invaded a host cell
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Which cell types do not have cell walls?
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ANIMAL CELLS
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Primary wall
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Formed by secreting strands of cellulose into the coating that forms and sticks adjacent cells together. It allows the cell to enlarge
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Middle lamella
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sticky later in between primary walls of abutting plant cells
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Secondary wall
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cells stop growing and begin to secrete material on the primary walls inner surface
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Ligin
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one of the materials secreted to form the secondary wall. Its an organic compound that makes up 25 percent of the secondary wall. It makes plants stronger, more waterproof, and less susceptible to plant attacking organisms
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Cuticle
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protective covering made of cell secretions. It helps protect exposed surfaces of soft parts and limits water loss
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Plasmodesmata
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Connect the cytoplasm of adjacent cells
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What is the type of extracellular matrix in plant cell walls?
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cellulose
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What is the type of extracellular matrix in fungi?
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chitin
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What is the type of extracellular matrix in animals?
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carbohydrates and proteins
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Tight Junctions
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links cells in most body tissues especially the ones that line outer surfaces, internal cavities and organs.
These junctions seal cells together so water soluble substances cannot pass between them |
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Adhering Junctions
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Anchor cells to one another and also to the extracellular matrix
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Gap Junctions
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connect the cytoplasm of adjacent cells. Substances flow quickly from one cell to another cell through these channels. Allows entire regions of cells to respond to a stimulus simultaneously
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Microtubules
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long hallow cylinders made up of subunits of protein tubulin
they rapidly assemble and disamble when needed |
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Microfilaments
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Fibers that consist of globular protein actin
They strengthen or change the shape of eukaryotic cells |
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cell cortex
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reinforcing mesh under the plasma membrane formed by crosslinking of microfilaments
the actin microfilaments at the edge of a cell drag or extend it in a certain direction |
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Muscle contraction
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brought about through myosin and actin microfilaments
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Intermediate filaments
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strengthen and maintain cell and tissue structures
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What is the most stable part of the cytoskeleton?
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intermediate filaments
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Motor proteins
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can move cell parts in a sustained direction when they are energized by ATP
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Train track image
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train: motor proteins
track: microtubules and microfilaments |
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9 + 2 array
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nine pairs of microtubules ringing around pair in the center
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centriole
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barrel shaped structure gives rise to the microtubles and then remains below the finished array as a basal body
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Pseudopods
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"false feet"
move the cell and engulf pray |
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What makes pseudopods move in a steady direction?
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They have microfilaments inside that elongate while motor proteins attached to these microfilaments drag the plasma membrane with them.
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Where are dynein arms?
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projecting from each pair of microtubules in a flagella or cilia
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What kind of protein is a dynein?
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motor protein that has ATP activity that cause the arms to repeatedly bind the adjacent pair of microtubules to bend and disengage
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