BIO104L

Independent variable

The factor that you test or alter during the course of the experiment

Dependent variable

The factor you measure, the type of data you are collecting

Constant variable

Factors kept the same in all the trials, help to make sure you are conducting a “fair test”

Experimental group

Group that you are tesing

Control group

Group that you are not testing

Positive control

A test in which you expect a positive result

Negative control

A test in which you expect a negative result

Importance of a standard curve

Determines the unknown concentration of a sample by comparing it to a set of known standards. Created by plotting known concentrations against their measured values, the curve is used to find the concentration by seeing where their measurements fall on the curve

Spectrometer

Tells how much of the chemical reaction has happened based on how strong the color change is. A more intense color change (darker purple) indicates a higher protein concentration

4 types of macromolecules

Carbohydrates, lipids, proteins and nucleic acids

Carbohydrates

Important energy source, composed of carbon, hydrogen and oxygen (1:2:1 ratio), one sugar unit (monosaccharide), disaccharides and polysaccharides. Examples are glucose, fructose and starch

Lipids

Long term energy storage molecules and hormones. Examples are butter and vegetable oil

Three classes of lipids

• Fats, oils and waxes

• Phospholipids

• Steroids

Phospholipids

One of the major components of cell membrane

Steroids

Male and female hormones and cholesterol

proteins

Building blocks of the body and serve as the major structural component of a diverse range of living parts including muscle tissue, enzymes and hair. Composed of one or more amino acids

Four structures of a protein

• Primary structure, Secondary structure, Tertiary structure and Quaternary structure

Benedicts test

Test for simple sugars, solution contains copper sulfate and when blue copper ions interact with many simple sugars the copper ions get reduced to CU+ and change color. The color change is a direct result of the amount of sugar that is reacting with the copper ions

Positive results for benedict’s test

Glucose and fructose

Negative results for benedict’s test

Distilled water, sucrose

Lugol’s Test

Iodine containing solution which reacts with starch causing a color change in the solution. It is a yellow/brown color that will change to dark blue/black when starch is present

Positive results for lugol’s test

Starch solution

Negative results for Lugol’s test

Distilled water, fructose and sucrose

Proper techniques for viewing a specimen on a slide using a microscope

Add a small drop of water to the slide. Start at the 4x or or lowest power objective with the coarse adjustment knob, then use subsequent objective lenses 10x (100x) then rotate to 40x (400x) with the fine adjustment knobs . Make sure the light is turned on and the slide is in place with the stage clips and is centered

Prokaryotic cells

Single cell organisms that lack a nucleus or membrane bound organelles, DNA is in the cytoplasm

• Bacteria and Archaea

Eukaryotic cells

Have a nucleus and membrane bound organelles

• Protists

• Fungi

• Animals

• Plants

Eukaryotic organelles

• Nucleus

• Chloroplasts

• Vacuole

• Mitochondria

• Smooth ER

• Rough ER

• Golgi apparatus

Prokaryotic and Eukaryotic cells organelles

Plasma membrane, cytoplasm, ribosomes and DNA

Plasma Membrane

Boundary for the cell, composed of a phospholipid bilayer with hydrophilic head and hydrophobic tails

Cytoplasm

Area inside the cell that is not part of the DNA region

Ribosomes

Particles in the cell the coordinate the synthesis of proteins

DNA

The genetic material of the cell

Cell wall

Secondary protective and supportive boundary that lies outside of the plasma membrane of bacteria, plants fungi and some protists

Nucleus

Organelle that houses the genetic material of the cell, site of DNA replication and RNA synthesis and bounded by two layers of membrane called the nuclear envelope

Chloroplasts

Organelles found in plant cells and some protist cells, function in photosynthesis are green because of pigment called chlorophyll

Vacuole

Large storage organelle found in plants that houses water, nutrients and other chemicals, pressure from the fluid in vacuoles helps keep plant cells rigid

Mitochondria

Major site of cellular respiration, process where chemical energy is made available for cellular use

Smooth ER

Series of interconnected tubes and channels site of lipids synthesis including phospholipids and cholesterol

Rough ER

Series of interconnected tubes and channels with ribosomes covering the surface, ribosomes are site of protein synthesis

Golgi apparatus

Proteins produced by the endoplasmic reticulum are sent here to be modified, sorted and packaged modifications include adding carbohydrates or cleaving large proteins

Selectively permeable

Some molecules and or water can move freely across the membrane, but other molecules will move slowly or not at all

Diffusion

Transporting substances across the cell membrane, molecules move from high to low molecular concentrations

Simple diffusion

Molecules cross biological membranes, such as the plasma membrane unaided

Facilitated diffusion

Some molecules due to their chemical properties or size cannot pass through the membrane on their own, so they are transported across the membrane by protein channels

Results of osmosis lab

• Starch never left the bag because it was too big

• Glucose left the bag because it had positive diffusion since the molecules are small

• If large amounts of protein are added to the bag the molecules would stay in the bag because they are too large

Hypertonic solution

water moves out of the cell

Hypotonic

Water moves into the cell

Isotonic

No net movement of water

Results of red onion cells

• When a cell was placed in 1% NaCl it expanded creating a hypotonic solution

• When placed in 10% NaCl it shrunk because it became a hypertonic solution

Enzymes

• Increase the rate of a reaction functioning as a catalyst

• Lowers the activation energy of a reaction

• Has an active site that and binds to a specific substrate

Substrate

Compounds or molecules that the enzyme reacts with, enzyme has a specific shape so that this is able to bind to it

Catalase

Common enzyme present in almost all organisms and its purpose is to protect cells from oxidative damage

Results of enzyme experiment

The enzyme catalase sped up the chemical reaction and when there was no enzyme present the reaction did not occur at all

cellular respiration

Chemical reaction in cells to create ATP it requires oxygen and carbon dioxide

Reactants of cellular respiration

Glucose, oxygen

Products of cellular respiration

Carbon dioxide, water and energy (ATP)

Results of exercise experiment

More carbon dioxide sped up the chemical reaction, BTB solution turned from blue to yellow because it reacts with the carbon dioxide, more carbon dioxide present after working out because the body is taking in more oxygen and creating more carbon dioxide waste

Phases of mitosis

Interphase, prophase, metaphase, anaphase, telophase and cytokinesis