EXPLORING CREATION WITH BIOLOGY

Modules 1A and 5

Characteristics of Life

1. All life forms contain DNA 2. All life forms have a method by which

they extract energy from the surroundings and convert it into energy that sustains them

3. All life forms can sense changes in their surroundings and respond to those changes

4. All life forms reproduce

1. All life forms contain DNA

Organization (The level of complexity)

• Organism• Organ System• Organs• Tissues• Cells• Molecules • Atoms/Elements

2. Energy Use

Energy Use a. Organisms need energy

constantly to build molecules (synthesis) and cells and to break down substances (such as food for nutrition or invading bacteria cells).

b. Organisms must transport nutrients to be used in cellular respiration to produce energy.

c. An organisms’ chemical reactions (all of which use or store energy) are called its metabolism

d. Used for growth and development

3. Respond to Stimuli

Respond to Stimulia. A quick, non-permanent changeb. Stimulus – any condition that causes an organism to

react.

Example – A loud noise (stimulus) causes your dog to run under the bed (response).Adjust to Environment

a. Homeostasis - the regulation of an organism’s internal environment to maintain conditions suitable for life

Ex: Sweating when you get hot to cool down Ex: Getting rid of wastes by excretion

4. All Life Forms Can Reproduce

Reproductiona. Important at the specie level (organisms must

replace themselves so the entire species will survive.)b. May occur only at a cellular level.c. May be asexual (only one individual contributes

genetic material) or sexual (two individuals contribute genes).

Scientific Method

Atoms, Molecules, Compounds

Majority of an atom’s properties are determined by the number of electrons

Physical Change Vs Chemical Change

Phases of Matter

Diffusion vs. Osmosis

Organic Macromolecules

CarbohydratesLipidsProteinsNucleic Acids

Carbohydrates

Carbohydrates - Functions

Functions of carbohydrates a. Energy is released when carbohydrates

are digested. This is because glucose is used for cellular respiration.

i. Monosaccharides (simple sugars) provide short term energy.

ii. Starch and glycogen are considered longer term energy sources because they can be broken down over a period of minutes, hours or days to provide glucose for energy.

Lipids

Functions of lipidsa. Because of the numerous bonds and the

way the body stores lipids, they can be used as very long-term (weeks, months) energy sources. Ex. Bears accumulate a layer of fat before winter (when food will be less available)

b. Fats stored in the body act as insulation and protection for internal organs.

c. Some hormones are composed of lipids (steroids).

Proteins

Functions of proteinsa. Some proteins absorb light to maintain

homeostasis. These are called pigments. They create color by reflecting certain wavelengths of light.

Ex. Chlorophyll absorbs light to gather energy for photosynthesis.

b. Some proteins are constructed by cells to bind with and inactivate foreign particles in the body. These are called antibodies.

c. Proteins may form structural parts in an organism – such as keratin in hair and nails.

Proteins - Continued

d. Some proteins are used for transport through the cell membrane or in the bloodstream (ex. hemoglobin)

e. Some proteins are used for communication between cells. These may be hormones (insulin) or neurotransmitters.

f. Enzymes (a special class of protein) act to speed up chemical reactions.

Enzymes

A. Enzymes help maintain homeostasis1. All organisms have metabolism. Metabolism

includes all of the chemical reactions that occur in that organism. Metabolism includes digestion and production. Metabolism (chemical reactions) requires certain conditions to occur. Enzymes regulate metabolism, allowing life to continue.

2. Metabolism (each reaction) has a small range of temperature and pH at which it can proceed. Each reaction also needs some energy to begin. This is called activation energy. Enzymes allow reactions to occur at lower activation energy (body temperature). This means enzymes act as biological catalysts (speeds reactions).

Graph With and Without Enzyme

Enzymes - Continued

2. Enzymes mediate (help) chemical reactions using a specific chemical pathway (series of steps).a. The enzyme collides with the substrate.b. The enzyme and substrate fit together at the

active site like a lock and key. c. The enzyme changes the substrate in some way

i. It may help break the substrate apart.ii. It may hold two (or more) substrates

together closely so the two parts interact.d. The enzyme and the substrate separate. The

substrate (now changed) is called the product.

Mr. Wanamaker's Enzyme Animations

Enzyme Visual

Enzyme Characteristics

1. Enzymes are biological catalysts. This means they speed up chemical reactions in living things.

2. Enzymes are specific. This means enzymes will catalyze only one specific reaction because only certain substrates fit due to the shape of the active site.

3. Enzymes are reusable. Notice in the diagram above that the enzyme did not change shape or split. This means it can now fit with another substrate or set of substrates and repeat its role in speeding up the reaction.Reversible Enzyme Reactions Animation

Nucleic Acids

A. Nucleic Acids

1. Carbon, hydrogen, oxygen, nitrogen, and phosphorus make up subunits called nucleotides. Many nucleotides bond together to make up a long chain – a nucleic acid.a. DNA is a double chain of nucleotides

found in all living cells.b. RNA is a single chain of nucleotides that

provides the structures needed for the cell to make proteins.

DNA Visual

DNA vs. RNA

Nucleic Acid Function

pH

Acids vs Bases

Acids and Bases

Acids vs. Bases - Properties