Hon. Bio Mid Term 2022

Scientific Method

General style of investigation

Is the scientific method a rigid, step by step process?

NO

Steps of Scientific Method-

Observing/asking questions, Form Hypothesis, Design controlled experiment, controlling variables, Collecting Data, Analyzing conclusions

Hypothesis

Tentative scientific explanation that can be tested further

Designing controlled expieraments-

testing your hypothesis. Design experiments that measure factors that can change

Controlling variables-

If many are changed, it becomes difficult to tell which variable is responsible for result

WHat two types of data can you collect?

Quantitative and Qualitative

Quantitative Data-

data deals with numbers

Qualitative Data-

data deals with descriptions (color/form)

Independant Variable-

Normal with Changed element

Dependent Variable-

Not Changed

Control group-

exposed to normal conditions

Scientific Theory-

Reliable Scientific explanation that relates to many repeated observations

Experimental group-

exposed to normal conditions, with the independent variable

Why do we use the Metric system?

Its more precise

If you want your unit of measure to get bigger, you move the decimal to the ____.

Left

Metric system-

Kilo, Hecta, Deka: UNIT :Deci, Centi, Mili

10 Decigrams= ___ Hectograms

.010 Hectograms

for volume you use:

Liters

Freezing point C

0

Boiling point C

100

Freezing point F

32

Boiling point F

212

Why use peer review?

Leads to new Questions, Ideas, and Theorys

Characteristics of Life (7)

Made up of cells, Reproduce, Based on universal genetic code, Grow/Develop, Respond to environment, Maintain Internal balance, And change over time

when are Covalent bonds formed?

When atoms share electrons

When are Ionic bonds formed?

When one or more electrons are FULLY transferred from one atom to another

Valence Electrons-

electrons in outermost shell

atoms that lose electrons become___ charged. atoms that gain electrons become ____charged

Positively, Negatively

Isotopes all have same number of ______.

Electrons

Isotopes all have same ______ _____.

Chemical Property

Isotopes differ in the amount of ____.

Neutrons

in Radioactive Isotopes:

The nuclei are _____ and break down at a ___ _____

unstable, constant rate

4 Macromolecules

Carbohydrates, Lipids, Proteins, Nucleic Acids

Carbohydrate elements-

Carbon, Hydrogen, Oxygen. 1:2:1 ratio

Carbohydrate monomer-

Monosaccharide

Carbohydrate function-

Main source of energy

Carbohydrate Example-

glucose, cellulose. starch

Lipid elements-

Carbon, Hydrogen, Oxygen

Lipid Monomer-

Fatty Acid

Lipid function-

Make waterproof coverings, make up bi-layer (membrane)

Lipid example-

Lard and Wax

Protein Elements-

Carbon, Hydrogen, oxygen, Nitrogen

Protein Monomer-

Amino Acids

Protein Function-

Structure; carry materials in/out of cell

Protein Example-

Enzymes and Hormones

Nucleic Acid Elements-

Carbon, Hydrogen, Oxygen, Nitrogen, Phophorus

Nucleic Acid Monomer-

Nucleotide

Nucleic Acid Function-

contains genetic material

Nucleic Acid Example-

DNA and RNA

Polar -

It has a charge (+,-)

Non-Polar-

No Charge (neutral)

Hydrogen Bonds-

bonds between different water molecules; these bonds are weak

Cohesion-

attraction between molecules of the same substance

Adhesion-

attraction between molecules of different substances

Capillary action-

H20 pulled up against gravity (H20 through roots)

Surface tension-

strong attraction between H20 molecules (supports lightweight objects)

Concave meniscus-

Adhesion is greater than Cohesion

Convex meniscus-

Cohesion is greater than Adhesion

Basic PH level-

8-14

Neutral PH level-

7

Acidic PH level-

1-6

Basic PH example-

Blood, Soap, Bleach

Neutral PH example-

Pure water

Acidic PH example-

Lemon, Vinegar, Coffee, Milk

Buffers-

 help maintain homeostasis in organisms

unbuffered base + acid = _____ pH

Acidic

buffered base + acid = _____ pH

Basic

Solutions-

the mix is evenly distributed (dissolved)

suspension-

mix NOT evenly distributed (dissolved)

solute-

substance being dissolved

solvent-

solute is being dissolved in this substance

Protons-

Positively charged, located in the nucleus

Neutrons-

Neutral, located in the nucleus

Electrons-

Negative charge, surround the nucleus

Atomic number-

Top of element card; states the number of protons in each atom

Atomic Mass-

Bottom of element card; States the number of protons and neutrons in each atom. (always round)

if reactants are A+B, products are _+_

C+D

Chemical reaction-

changes one set of chemicals into another

reactants-

Engage in chem. reactions

products-

What is produced by a chemical reaction

catalyst-

 substance that speeds up a reaction

how does an enzyme speed up a chem. reaction?

by lowering the activation energy

Enzyme-

Protein that speeds up chemical reactions that take place in cells

Substrate-

Binds to a site on the enzyme called the active site

Some Conditions that change the Enzyme affecting the activity are-

Temperature and PH

When an enzyme’s pH or temperature reaches a non-optimum level, the enzyme becomes _______

Denatured

Denaturing means-

The change caused bonds to be broken and the enzymes to stop functioning

In an energy absorbing reaction, energy starts ___ and ends___

low, high

In an energy releasing reaction, energy starts ___ and ends___

high, low

Cell Theory-

All living things are made up of cells; New cells are produced from existing cells; Cells are the basic units of structure and function in living things

Why are microscopes used?

To see small things we cant with the naked eye

_________microscopes much more powerful

Electron

Light Microscopes-

Focuses light to view samples; samples can be living

Electron Microscopes-

Focuses a beam of electrons to view samples; samples are dead

Types of electron microscopes:

Transmission and Scanning

Transmission-

Samples cut into thin slices to be viewed; viewed in 2D

Scanning-

 Samples are viewed in 3D

Eukaryotic vs Prokaryotic

Prokaryotic lacks a nucleus and membrane bound organelles

What type of DNA does prokaryotic have?

Circular