honors bio midterm

Observation

\-Uses all 5 senses

\-2 types

Qualitative: quality (ex: color, shape) *better one*

Quantitative: measurement (ex: temperature, mass, dimensions)

Inference

\-Educated guess based on observations

\-Where your hypothesis comes from

Steps of the Scientific Method

1. Question/ observations
2. 2. Research
3. 3. Hypothesis (if, then statement) (includes both variables, specific)
4. 4. Experiment
5. 5. Data analysis
6. 6. Conclusion (refer back to hypothesis)

Independent Variable

The variable that is manipulated or changed (in a good experiment there is only 1)

Dependent Variable

The variable you are measuring. It is the response to what you manipulated or changed

Basic units of measurement

1. Volume- how much space something takes up (liter...pipette, graduated cylinder)
2. 2. Mass- how much of something there is (gram...balance)
3. 3. Length- measure of the distance (meter...ruler)

Data table

\-Independent variable should be on the left

\-Dependent on the right

\-Be specific!

Graphs

\-Independent on the X axis

\-Dependent on the Y axis

\-Bar graphs are used to compare how each independent variable tested responded to the dependent

\-Line graphs are to show the relationship between the two variables

Beaker

mix and measure solutions

Graduated Cylinder

Measure volume (more accurate than beaker)

Erlenmeyer flask

make and store solutions

Volumetric flask

make and store solutions

Test tube

run tests

Test tube holder

holds one test tube

Test tube rack

holds many test tubes

Pipette

measure smaller volumes

Coverslip

covers the specimen

Glass slide

Put specimen on the glass slide

Dissecting scissors

To cut skin & thin bones

Dissecting tray

Where you put the specimen you're dissecting

Forceps

(tweezers) to pull away tissue

Blunt probe

point/move when you dissect

Eye dropper

a way to transfer a liquid

Scalpel

cut thin skin/tissue

Funnel

helps to pour something in a smaller container

Magnifying glass/hand lens

to see smaller things better

Microscope

magnifies to 40-100 times

Stereoscope

magnifies to 10-40 times

Petri dish

to store growth like bacteria, yeast, or fungus

Agar

gel substance in bottom of petri dish

Inoculation loop

transferring bacteria to another place

Thermometer

measures temperature (celsius)

Balance

mass (grams)

Metric ruler

distance (meters, cm, in)

Electrophoresis Chamber

cuts up DNA based on size

4 groups of organic compounds

1. Carbohydrates (sugars and starches)
2. 2. Lipids (fats, oils, waxes, steroids)
3. 3. Proteins (enzymes, hormones)
4. 4. Nucleic Acids (DNA & RNA)

Carbohydrates

Basic unit: monosaccharide (carbon, hydrogen, oxygen) (C6H12O6)
Examples of monosaccharides: one molecule

1\. Glucose (plants make through photosynthesis)

2\. Galactose (found in milk)

3\. Fructose (found in fruit)
Examples of Disaccharides: two molecules

1\. glucose + glucose ----> Maltose + Water

2\. glucose + glucose ----> Lactose + Water

3\. glucose + glucose ----> Sucrose + Water
Examples of polysaccharides: many monosaccharides bonding

1\. starch ---> how plants store extra glucose

2\. glycogen -----> how animals store extra glucose

3\. cellulose -----> found in the cell wall of plants

Lipids

Basic unit: fatty acid (carbon, hydrogen, oxygen)

Hydrophobic ----> fears water (nonpolar)

Hydrophilic ---> water-loving (polar)

(Lipid) Saturated fat

\-the hydrocarbon chain is saturated with hydrogens...therefore there are no double bonds in the chain (straight)

\-not good for you

(Lipid) Unsaturated fat

\-double bonds are in the hydrocarbon chain

\-cannot solidify because the double bonds---> cause a "kink"

\-usually fats from plants

Proteins

Basic Unit: amino acid (carbon, hydrogen, oxygen, nitrogen)

\-Basic unit includes amino acid and a carboxyl group

\-types of proteins: hormones and enzymes

(Protein structure) Primary

\-amino acid sequence

\-what determines the 3D conformation

(Protein structure) Secondary

\-coils and folds made by polypeptide chain

\-coils caused by hydrogen bonds at regular intervals along the polypeptide chain

**alpha helix: coils held together by H-bonds**

pleated helix: 2 regions of the polypeptide chain lie parallel to each other

(Protein structure) Tertiary

\-the overall, 3D shape of the polypeptide

\-most are described as globular (blob) or fibrous (rope)

\-results from interactions between the R groups

\-caused by hydrophobic interaction

\-Disulfide bridges: strong covalent bonds that reinforce the protein conformation

(Protein structure) Quaternary

\-the overall structure that results from the combination of more than one polypeptide folded chain

\-Examples: collegen, hemoglobin

What is denature and what causes it?

it is the unfolding or breaking up of a protein, modifying its standard three-dimensional structure. Proteins may be denatured by chemical action, heat or agitation causing a protein to unfold or its polypeptide chains to become disordered typically leaving the molecules non-functional.

How do enzymes work?

\--->a type of protein that speeds up a reaction

a. weakens chemical bonds to make them easier to break

b. very specific to what molecule (substrate) it works on

c. things can affect how well enzymes work

What are the types of enzyme inhibitors?

\-Competitive inhibitor= block substrate from entering active site

\-Allosteric inhibitors= bind to another part of the enzyme causing it to change shape and therefore unperceptive to the substrate

\-Noncompetitive inhibitor= bind to another part of the enzyme causing it to change shape, but not so much that a reaction can't take place. Reactions occur, just slower

(Enzymes) How can the rate of reaction be affected?

\*\*\*concentration of enzyme=increase rate

\*\*\*temperature of environment= increase rate

\*\*\*pH environment= optimal range

\*\*\*Enzyme inhibitors (poisons, antibiotics)

Nucleic Acids

\-made of carbon, hydrogen, oxygen, nitrogen, and phosphorus

\-monomer= nucleotide

\-polymers= DNA & RNA

Cell theory

\-all living things are made of cells

\-cells come from biogenesis theory

\-cells are the basic unit of all life
\----> some experiments helped to prove this theory (Reid's experiment: meant container, Pasteur's experiment: flask with open air, Spallanzani's experiment: flask experiment)

Cell diversity (Shape)

\--->different shapes because they have different functions

a. nerve cells (long extensions to give & receive messages)

b. skin cells (to protect)

c. red blood cells (biconcave shape to carry more oxygen)

Cell diversity (Size)

-there is a limit of size due to the speed at which materials need to get to the center of the cell

Cell diversity (internal organization)

Prokaryotic cells: (ex: bacteria)

\-no nucleus

\-no membrane-bound organelles Eukaryotic cells: (ex: plants, animals, fungi)

\-nucleus

\-membrane bound organelles

Why are cells small?

Cells are so small because they are easier to replace, and a cell needs to be small to be able to perform the tasks a cell needs to do. If cells were bigger it would be harder for the body to replace the cell without disrupting what is going on in the body and delaying a process.

Cell membrane structure

\-aka plasma membrane

\-Separates cell from its external environment

\-Gives shape and flexibility to the cell

\-Made of two layers because of the polarity

\-made of fats (phosphates) and proteins

\-Cholesterol is also a part of the membrane

\-There are small carbohydrates attached to the outside that serve as "tags" so the organism can identify the cell

\-"Fluid Mosaic Model" is how scientists refer to its structure

Cytoplasm vs. Cytosol

\-Cytoplasm is the gel-like fluid inside the cell

\-Cytosol is the jelly-like material in the cytoplasm that contains water, salt, sugars, fats, and proteins (always moving)

Ribosome

-makes proteins (puts together amino acids)

Rough ER

\-Makes, packages, and transports proteins for export

\-Called "rough" because it is covered in ribosomes

Smooth ER

-Makes, packages, and transports fat (phospholipids and steroids)-"Smooth because it has no ribosomes

Golgi apparatus

Polysaccharides are made and attached to proteins & phospholipids (maintains cell membrane)

Mitochondria

Where cellular respiration takes place (burning food to make energy)

Lysosomes

Digests food, old cell parts, and foreign material

Microtubes

-Large fiber of cytoskeleton that supports and gives shape to the cell

Microfilaments

Involved in cell division (mitosis)

Cilia

Move the cell OR move things around the cell

Flagella

Moves cell

Nucleus

-Protects and contains the DNA-"safe place"

Nuclear envelope

Double membrane perforated with pores that control the flow of materials in and out of the nucleus.

Nucleolus

Makes ribosomes

Vacuole

-Stores "stuff" (food, waste, water, pigment, fat, poison...)

Difference between animal and plant cells

Animal:

\-no cell wall

\-no rigid shape

\-no chloroplasts

\-some have small vacuoles

\-has lysosomes
Plant:

\-thick rigid cell wall

\-rectangular shape

\-has chloroplasts

\-large central vacuole

\-no lysosomes

Homeostasis

process by which organisms maintain a relatively stable internal environment

Diffusion

movement of molecules from an area of greater concentration to lesser concentration

Concentration gradient (equilibrium)

\-difference of concentrations across a space/membrane

\-Equilibrium: no NET movement of molecules across a space

Concentration

-amount of solute per unit of solvent

Solute

molecules being dissolved into a solution

Solvent

a substance capable of dissolving another substance (usually water/a liquid)

permeablesemipermeableimpermeable

Permeable: molecules CAN go through the membrane

Semipermeable: allows SOME substances to cross the membrane (membrane is selective, based on size/polarity/charge)

Impermeable: not permitting passage through the membrane (big molecules/have a charge)

Osmomis

the diffusion of water molecules across a selectively permeable membrane

HypertonicHypotonicIsotonic

Hypertonic: more concentrated

Hypotonic: less concentratedIsotonic: equal concentrations

Tugor pressure

Pressure in a plant cell due to water flowing through it

Plasmolysis

When a plant cell collapses on itself because it lost too much water

Cytolysis

when an animal cell breaks/bursts because it has taken in too much water

Contractile Vacuole

vacuoles that pump water out of a cell to keep a concentration gradient present

Active transport

when a molecule uses a protein in the cell membrane to move against the concentration gradient (requires energy)

Facilitated diffusion

when molecules move down the concentration gradient with the help of a protein in the cell membrane (no energy required)

Endocytosis vs. Exocytosis

Endocytosis : taking in the vesicle

Exocytosis : vesicle leaving golgi apparatus on cell

What is cellular respiration?

A process all cells do of using food to make energy in the mitochondria

What does our body use as energy? How is energy obtained from this?

1. A molecule called ATP
2. 2. Used for several kinds of work:

\-Mechanical work (muscles contracting)

\-Transport work (any kind of active transport)

\-Chemical work (enzymes, reactions)

Structure of ATP

adenine, ribose, 3 phosphate groups

Overall equation of cellular respiration

C6H12O6 + 6O2 --\> 6CO2 + 6H2O + 38ATP

Glcolysis

\-"sugar splitting"

\-occurs in the cytoplasm

\-Glucose uses 2 ATP to create 2 G3P molecules and then 2 ATP is added to create pyruvic acid

Krebs cycle

\-when carboxyl groups on the acetyl

\-CoA molecule are lost as CO2 and NADH molecules are produced

\-occurs in the mitochondria matrix

Electron Transport chain

\-all the NADH's produced in glycolysis, grooming, and Krebs goes to the cristae of the mitochondria

\-electrons get passed down the chain (because each is more electronegative than the last) and it utilizes chemiosmosis and the energy of the H+ gradients across a membrane to phosphorylate ADP to make ATP

Chemiosmosis

using the energy of H+ gradient across a membrane to phosphorylate ADP to make ATP, the flow produces energy that is used to pump H+ions across the membrane (active transport)

How many ATP's are produced from one glucose molecule?

38

Anarobic vs Aerobic respiration

Anaerobic:

\-when oxygen is NOT available

\-occurs when an athlete is exercising too vigorously there's not enough oxygen delivery into the muscle.

Aerobic: when oxygen IS available

lactic acid fermentation

\-used in our cells and bacteria

\-pyruvic acid ----> lactic acid-muscle cramps, burning, and soreness due to lactic acid buildup

\-use process to make yogurt and sauerkraut

\-Makes 2 ATP

Alcoholic fermentation

\-used by yeast and bacteria-pyruvic acid ---> ethyl alcohol +CO2-use process to make wine, beer, and bread

\-Makes 2 ATP