BIO101 Lab Quiz 2

chemical indicators

substance that gives visible sign, usually by a color change, of the presence/absence of a certain concentration of a chemical

biomolecule

any molecule present in living organism

example of chemical indicator

pH strip/paper

monosaccharide

one sugar molecule, building blocks of di/polysaccharides

disaccharide

sugar formed when two monosaccharides are joined

polysaccharide

carbohydrate whose molecules consist of many sugar molecules

benedict test tests for…

reducing sugars

positive benedict test

yellow to red, yellow being lowest concentration red being highest

negative benedict test

blue, if green there is a trace of reducing sugars

iodine test tests for…

starch

positive iodine test

dark purple/black

negative iodine test

maroon/organge/brown

positive control group

always turns expected color, like glucose in lab report

negative control group

doesnt react, like distilled water

lipids

non-polar compounds insoluble in water

lipids are used for…

energy storage and building cell structure

sudan III test tests for…

lipids

positive sudan III test

strong red color (separation)

negative sudan III test

pale red, all mixed

proteins

basic unit is an amino acid

bonds between amino acids are…

peptide bonds

biuret test tests for…

peptide bonds NOT amino acids/proteins

positive biuret test

purple

negative biuret test

blue

nucleic acids

largest biomolecule, make up 1-2% of living organisms, building blocks of RNA and DNA

dische diphenylamine test tests for…

nucleic acids

positive dische diphenylamine test

blue

negative dische diphenylamine

clear

compound light microscope

two lenses, so they combine/compound effects

compound light microscope advantage

can see things on micro level, 10-6

disadvantages compound light microscope

light has to be able to pass through specimen

Dissecting Microscope/Stereoscope

used for larger objects, see fine details in macroscopic objects

advantage Dissecting Microscope/Stereoscope

can see larger objects

disadvantage Dissecting Microscope/Stereoscope

dont get great magnification (only about 40)

physical precautions of microscope

• carry microscope w two hands, one on arm one on base

• do not remove parts

• do not tilt

• keep stage clean

• use only lens paper and cleaner

• never use coarse adjustment under high power/oil immersion lenses

• always begin with lowest power/shortest lens

• keep both eyes open

• when placing/removing slide make sure stage is lowered

eyepiece/ocular lens

lens you look through, magnifying power of 10x

objective lens

mounted on nosepiece

nosepiece

upper part of a compound microscope, holds objective lens, revolves/rotates

stage

flat platform where slides are placed

stage clips

clip on stage to hold in place

mechanical stage knobs

moves stage back and forth, side to side

rheostat

controls amount of light “dimmer switch”

condenser lens

concentrates light on specimen and increases resolution

arm

supports tube and connects it to base

base

bottom of microscope, support

course focus

closer to the body, visibly see stage rising/lowering

fine focus

on coarse focus knob, tiny movements to stage

iris diaphragm

contains amount of light that can enter through specimen

parfocal

if it is in focus with one object, when objective is rotated it will remain in focus

resolution

shortest distance between two points on a specimen that can still be distinguished by the observer— higher magnification = lower resolution

how to calculate magnification?

ocular lens is ALWAYS 10x, so 10x TIMES the objective

three cell theories

1. all living organisms made up of cells

2. cell basic unit of life

3. cells come from pre-existing cells

common characteristics of cells

1. plasma membrane

2. store genetic information in form of DNA

3. everything in cell is in cytoplasm, everything in nuclear membrane in nucleoplasm

prokaryote vs eukaryote

prokaryotes have no nucleus

bacteria shapes

coccus, bacillius, spirilium

coccus

round, bunched together

bacillius

rod-shaped

spirilium

spiral shaped bacteria

prokaryotes contain

cell wall, plasma membrane, cytoplasm, DNA, ribosomes

cell wall

outside of cell membrane

plasma membrane

phospholipid bilayer, inside cell wall

cytoplasm

internal substance of cells

DNA in prokaryotes

fine threads of DNA

ribosomes in prokaryotes

protein synthesis

main structures in eukaryotic cell

vacuoles, nucleus, cell wall, cell membrane, mitochondria