Bio Lab Midterm

Physiology

Physiology

Chemical processes that allow individual cells to function

Active transport

Those powered by cells energy containing molecules, ATP

Passive transport

Those powered by the molecular movement resulting from thermal heat energy

Diffusion

Where molecules or particles display net movement

Net movement

Molecules in an area of high concentration move to area where they are low in concentration until they reach equilibrium

Osmosis

The diffusion of water molecules across a semipermeable membrane

Solvent

Considered water

Solutes

Atoms or molecules

Semipermeable membrane

Means that some particles can freely move across the membrane while other particles cannot freely pass across it

Osmometer

An instrument used to measure the osmotic pressure of a solution.

Hypertonic

A solution that has a higher concentration of solutes compared to another solution, leading to water moving out of cells placed in it.

Hypotonic

A solution that has a lower concentration of solutes compared to another solution, causing water to move into cells placed in it.

Isotonic

A solution that has an equal concentration of solutes compared to another solution, resulting in no net movement of water into or out of cells.

Metabolism

Refers to the set of all chemical reactions that occur within a living organism

Enzymes

Usually are proteins that act as catalysts, substances that speed up specific chemical reactions but are not used up in that reaction (most end in -ase)

Digestion

The enzymatic breakdown of a molecule into its smaller subunits

ATP

The main source of usable cellular energy

How is ATP made in an organism?

It is produced from glucose by aerobic cellular respiration (glucose + 6O2 → 6CO2 + 6H2O + ~36 ATP)

How do organisms make ATP when there’s no oxygen present?

Via anaerobic cellular respiration

Fermentation

There are two types of fermentation, alcohol (glucose → ethanol + 2ATP) and lactic acid fermentation (glucose → lactic acid + 2ATP)

The disaccharide lactose is digested by lactase to make…

Glucose and galactose

Amylase digests starch to make…

Maltose

Yeasts are eukaryotic, single celled fungi well known to carry out…

Alcohol fermentation

Photosynthesis

The metabolic process used by autotrophic organisms to make glucose (6CO2 + 6H2O + sunlight → glucose + 6O2)

Where does photosynthesis occur?

Inside Chloroplasts

Where do the light reactions take place?

In the thylakoid membranes

Where does the Calvin benson cycle take place?

In the stroma

fermentation tube

calvin benson cycle

in prokaryotic autotrophs such as cyanobacteria, the chemicals needed for this cycle are free-floating in the cytoplasm, and the thylakoids are just infoldings of the plasma membrane

chlorophyll a

a green pigment necessary for photosynthesis to occur, and it is located in the thylakoid membranes

absorption spectrum

a graph showing which wavelengths of light a pigment will absorb and thus utilize for photosynthesis (a high peak indicates a high absorption at that wavelength)

chlorophyll a

every photosynthetic organism contains this pigment, it is called the primary pigment involved in photosynthesis because it starts the entire chain of chemical reactions that convert solar energy into chemical energy

antenna/accessory pigments

all other pigments, they gather other wavelengths of light and pass that energy on to chlorophyll a

chromatography

a technique used in analytical chemistry to separate chemicals dissolved in a solution based on how fast differently sized molecules migrate with a solvent front

cell cycle

refers to all the events and processes that occur as a cell matures, prepares for, and undergoes division

germ/stem/meristem cells

remain in the cell cycle, actively dividing and making more cells

dividing eukaryotic cells share the following cell cycle pattern…

1. interphase: where a cell grows, matures, functions, copies its DNA and prepares for division

2. nuclear division (mitosis): which separates copies of DNA depending on the type of cell needed by the organism

   1. cytokinesis: where the whole cell divides into 2 or 4 cells, depending on the type of nuclear division

mitotic cell division

occurs when one parent cell divides into two daughter cells that are genetically identical to each other with the same number of chromosomes as the parent cell

interphase is separated into how many subparts?

4; G0, G1, S, G2

meiotic cell division

only occurs in organisms when they are reproducing sexually

chromosome

a linear chunk of DNA

centromere

an area on the chromosome where microtubules can attach and sister chromatids are attached

chromatid

is one half of a replicated chromosome

chromatin

mixture of DNA and proteins that form chromosomes (loose, not in a tight format like chromosomes)

prophase

the first stage of cell division, where chromosomes become visible as paired chromatids and the nuclear envelope dissappears

spindle pole (MTOC - microtubule organizing center)

center found in cells where microtubules emerge

spindle fibers (spindle microtubules)

long protein ropes that come from the MTOC and connect at the centromere of the chromosome

asters (astrial microtubules)

a cellular structure shaped like a star, formed around each centromere during mitosis

metaphase

second stage of cell division, chromosomes become attached to spindle fibers, in the middle of the cell, forming a metaphase plate

anaphase

centromeres divide and microtubules attached to kinetochores pull sister chromatids apart and to opposite poles

telophase

the unreplicated chromosomes, formerly sister chromatids, reach the poles. The nuclear envelope reforms, chromosomes begin to decondense

cytokinesis

separation of other cellular materials

cell plate

a structure that forms when the cytoplasm of a plant cell divides

cleavage furrow

pinching off of a cell to make 2 sister cells

blastula

a particular stage in animal embryo development, where all cells of the embryo are actively undergoing mitotic cell division to produce many cells

the meristematic region of a plant (root and stem tips)

is where cells are continually dividing for elongation of roots and shoots

science

a way of thinking and a systematic method of investigating the world around us

general steps of the scientific method

1. make observations, and ask questions about those

2. do a literature search for relevant information and determine what is already known on the topic

3. develop hypotheses to answer the questions

4. design an experiment or observational study to test the hypotheses

5. carry out the experiment or study and gather data

6. summarize and analyze results (often mathematically/statistically)

7. make conclusions - compare observed results to what you expect for each hypothesis. Accept or reject each hypothesis

observations

interact with something and note what you see or experience. Observations should NOT include explanations

hypothesis

an educated guess. a testable, falfsifiable statement that potentially answers the research question

null hypothesis

state that there will be no difference or effect

alternative hypothesis

state that there will be a difference or an effect

prediction

what you expect to happen in your particular study if that hypothesis is supported

independent variable

is what is varied during the experiment

control

is the “normal” condition or absence of what you are sutdying

dependent variable

is what you measure, count or record; the kinds of data that a re gathered

constant

a factor or condition that is not changed throughout the experiment

sample size

the use of sufficent numbers of individuals or samples for each independent variable to ensure you obtain valid results for that variable

replicate

is each individual or sample being used to test the independent variable

experimental study

• is the classic scientific experiment, often performed in the lab

• some variables are controlled and some are manipulated

• looks to see if the manipulation had some sort of effect or difference

• cause and effect can be determined

observational study

• is often employed when research is conducted in a natural setting

• variables are not manipulated (no control or manipulated treatments)

• comparisons are made among different scenarios (organisms, plots, sites)

• cause and effect cannot be determined

bar vs. line graph

line graphs are best for chronological studies where data are collected on the same samples or individuals over a time fram or where the same samples or individuals are given different treatments at different times. bar graphs are best for showing categorical data (different kind of treatments on different individuals)