Living Environment Midterm Review

Accident or injury reporting

If an accident or injury occurs in the lab, you should report it to the teacher.

Fire safety tools

In the event of a fire, a fire blanket or fire extinguisher can be used.

Test tube safety

You should never stopper a test tube while heating it because it can explode.

Most important safety rule

Always follow directions.

Organism

An organism is the biological term for a living thing.

Line graphs

Line graphs usually show how one or more variables changes over a period of time.

Measurement units

Meters measure distance, liters measure volume, & Mass is measured in grams.

Centrifuge

A centrifuge separates material according to density.

Gel electrophoresis

Gel electrophoresis uses electricity to separate DNA fragments.

Indicator

An indicator changes color in the presence of a specific substance.

Compound light microscope

This microscope we use in class utilizing two lenses is called a compound light microscope.

Microscope image orientation

Image always appears upside down and backwards.

Ocular or eyepiece

Piece of microscope you look through usually magnifies 10 x.

Total magnification

Total magnification is found by multiplying the magnification of the ocular x objective.

Field of view

The area you can see when looking through a microscope is called the field of view.

Field of view under high power

Under high power, the field of view is smaller.

Image brightness under scanning power

An image is brighter under scanning power.

Diaphragm function

The diaphragm controls the brightness, amount of light.

Wet mount slide preparation

When preparing a wet mount slide, always place the slide cover at an angle to minimize air bubbles.

Staining a specimen

Staining a specimen is used to make cell parts more visible; staining kills the specimen.

Electron Microscopes

Electron Microscopes have the highest magnification; they can see viruses.

Scientific Inquiry

Scientific Inquiry is the development of explanations and theories.

Observation

An observation is information collected using the five senses.

Inference

An inference is not always a fact; it is a conclusion based on observations.

Scientific method

The scientific method is a process of organizing experimentation to solve a problem.

Steps of the scientific method

The 7 steps of the scientific method are define the problem, gather data (research), make a hypothesis, perform a controlled experiment, collect & analyze data, draw a conclusion, repeat.

Problem statement

A problem must be written in the form of a question.

Hypothesis statement

A hypothesis must be written in the form of a statement.

Controlled experiment groups

In a controlled experiment, you should have 2 groups: controlled group and experimental group.

Independent variable

All conditions will be kept the same between the two groups EXCEPT for the one factor being manipulated, this is the variable I control, known as the independent variable (the cause).

Dependent variable

The dependent variable is what is being affected by the independent variable.

Hypothesis 'if' portion

In a hypothesis, the 'if' portion of the statement is the independent variable.

Control group

The standard to which comparisons are made in an experiment is called the control group.

Constant variable

A constant variable is any variable that is the same for all test subjects.

Dependent variable graphing

When graphing your results (data), the dependent variable goes on the Y-axis.

Conclusion

Your conclusion must either support or refute your hypothesis.

Good experiment practices

Three ways to ensure a good experiment are use a large sample size, have only 1 independent variable, repeat the experiment.

Theory

An explanation of a natural phenomenon supported by many observations (evidence) and experiments over time is a theory.

Ethics

Ethics are moral values or principles.

Energy storage

Energy is stored in chemical bonds.

Inorganic compounds

Inorganic compounds can include any element but cannot contain both Carbon & Hydrogen.

Organic compounds

Organic compounds must contain Carbon AND Hydrogen.

Inorganic molecules examples

H2O, CO2, and O2 are examples of inorganic molecules.

Organic compounds list

The 4 organic compounds are carbohydrates, lipids, nucleic acids, proteins.

Lipid subunit

The subunit of a lipid is made of 1 glycerol and 3 fatty acids.

Starch composition

A starch is made up of simple sugars (monosaccharides - GLUCOSE).

Carbohydrates vs Lipids

Carbohydrates serve as an energy source, while lipids store energy.

Carbohydrates structure

Carbohydrates have ring-shaped molecules.

Elements in carbohydrates and lipids

Carbohydrates and lipids contain the elements carbon, hydrogen, and oxygen, but only carbohydrates have a 2:1 ratio of Hydrogen to Oxygen.

Nucleic acids building blocks

The building blocks of nucleic acids are nucleotides.

Nucleotide composition

A nucleotide contains a phosphate, sugar, and nitrogen base.

Proteins building blocks

The building blocks of proteins are amino acids.

Elements in proteins

Proteins contain the elements carbon, hydrogen, oxygen, nitrogen.

Protein function

A protein's shape defines its function.

Enzymes

Enzymes are a type of protein.

Chemical reaction results

In chemical reactions, the end results are the products.

Synthesize

To synthesize means to build or make a larger molecule from smaller ones.

Digest

To digest is to break down (lysing) molecules into smaller ones.

Catalyst

A catalyst speeds up a reaction.

Enzymes in reactions

Enzymes help speed up a reaction but are not used in the reaction so can be reused.

Lock and key model

The lock and key model states each enzyme's specific shape only fits with one substrate.

Factors affecting enzymes

The factors that affect enzymes are temperature, pH, and enzyme-substrate concentration.

pH scale

The pH scale measures acids and bases.

pH

The more acidic, the lower the pH.

Benedict's solution

Tests for glucose.

Iodine

Tests for starch.

Photosynthesis

Taking CO2, water, and sunlight to make glucose and oxygen.

Cellular respiration

The opposite of photosynthesis.

Metabolism

The sum total of all life activities.

Regulation

The control and coordination of activities of organisms. Response to stimuli.

Synthesis

To build. Using smaller molecules to make larger ones.

Transport

The absorption and circulation of materials throughout an organism.

Respiration

The life process involved in breaking down glucose to generate energy.

Nutrition

Involves three processes: ingestion, digestion, egestion.

Autotrophs

Can make their own food (plants, some bacteria).

Heterotrophs

Organisms that cannot make their own food.

Growth

The increase in cell size and/or the number of cells in an organism.

Excretion

The removal of the waste products produced by the organism (metabolic wastes).

Reproduction

Not needed by the individual to survive, but is needed by the species.

Homeostasis

Depends on all life functions working together. Keeps the organism stable (healthy).

Levels of organization

From small to large: molecule, organelle, cell, tissue, organ, organ system, organism.

Prokaryotic cells

Do not have a nucleus or membrane-bound organelles.

Eukaryotic cells

Have a nucleus that contains DNA.

Cell membrane

The barrier around the cell that regulates what enters and exits.

Nucleus

The control center of the cell.

Ribosomes

The site of protein synthesis.

Cytoplasm

Fluid within the cell, primarily made up of water.

Mitochondria

The site of cellular respiration (breaking down glucose to release energy in the form of ATP).

ATP

Adenosine triphosphate... is energy.

Chloroplasts

Where photosynthesis occurs in plants.

Vacuole

Stores food, water, and waste in a cell.

Selectively permeable membrane

Allows some substances in and keeps others out.

Phospholipid bilayer

The cell membrane is primarily made of a phospholipid bilayer (2 layers of lipids) and proteins.

Fluid-mosaic model

Describes how the components of the cell membrane are not in fixed positions.

Diffusion

Requires no energy. Movement from high to low concentration.

Active transport

Requires energy to move materials across the cell membrane from low to high concentration.

Osmosis

Diffusion of water through a selectively permeable membrane.

Hypertonic solution

When placed in a hypertonic (salty) solution, an animal cell will shrivel and a plant cell vacuole will collapse.

Hypotonic solution

Has a lower concentration of solute than inside the cell, so water will diffuse into the cell.

Starch

A large molecule that will not pass through a cell membrane.