BSC 108; Kennedy Exam 1

What are the levels of biological organization?

atoms, molecules, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, biosphere

List properties common to all living things

Complex/ structure. Organized. Grow and Reproduce. Respond to Stimuli. Acquire materials and use energy (metabolism.) Use DNA for hereditary information. Adapt to their environment.

What is homeostasis?

process of keeping internal conditions such as temperature constant in an organism.

What are the three domains of living organisms?

Bacteria, Eukarya, Archaea

What type of organisms does "Bacteria" have?

prokaryotic

What type of organisms does "Archaea" have?

prokaryotic

What types of organisms does "Eukarya" have?

eukaryotic

What are the steps of the scientific method?

1. Ask a question. 2. Do background research 3. Develop a hypothesis. 4. Test hypothesis in an experiment. 5. Analyze your data and draw a conclusion. 6. Communicate your results

How is a hypothesis different from a theory?

A hypothesis is a tentative answer to a question that can be tested and the test can prove the hypothesis false. A theory is the result of a hypothesis that has been tested and HAS developed an explanation that proves it true. Example of scientific theory - Theory of evolution by natural selection.

T/F An element is a substance that can't be broken down into another substance by ordinary means

TRUE

What are the three components of an atom?

protons, neutrons, electrons

Describe protons, neutrons and electrons

protons are positively charged. neutrons are neutral of charge. Both are located in the nucleus of the atom. Electrons are negatively charged and reside in the electron cloud.

T/F Electrons are found in the nucleus of a cell

FALSE; Electron cloud

How do you calculate atomic number?

It is the number of protons

How do you calculate atomic mass?

Protons plus neutrons

Understand how an atom can donate an electron to another atom or accept an electron from another atom to become an ion.

One atom has to many electrons and another atom doesn't have enough electrons. Once transfer happens, the atoms are now electronically charged (positive or negative).

What is an ionic bond?

Bond between a metal and a nonmetal; "taken not shared" electrons. An ionic bond is created when two oppositely charged ions come together (attraction).

What is a covalent bond?

Two non-metals; shared electrons. Covalent bonds hold atoms together and are created when two atoms share one or more pairs of electrons. The covalent bonds form a molecule.

What happens in a chemical reaction?

Break chemical bonds to form new substances

What is a polar covalent bond or polar molecule?

A polar covalent bond is a type of bond between two or more atoms in which the atoms do not share their pair of electrons equally. In this type of bond, one of the atoms is stronger than the other and attracts the electrons so that they spend more time closer to the stronger atom. A polar molecule is a molecule that has uneven distribution of charges (water).

T/F Water is a polar molecule composed of two hydrogen atoms and one oxygen atom

TRUE; H2O

What type of bonds does water make?

hydrogen bonds; weak

What are water's five unique properties

good solvent, high specific heat, cohesive and adhesive, polar, ice floats

What does hydrophilic mean?

Tends to mix with water; hydroxyls love water

What does hydrophobic mean?

tends to repel or not mix with water; nonpolar molecules don't like mixing with water.

What is the basic difference between an acidic solution and a basic solution?

An acidic solution has a low pH (below 7.0) and a basic solution has a high pH (above 7.0)

What are the four major classes of large molecules?

carbohydrates, lipids, proteins and nucleic acids

T/F Large molecules (polymers) are composed of smaller subunits (monomers)

TRUE

What is a dehydration reaction?

Losing a water molecule; two subunits covalently bond through loss of water molecule

What is hydrolysis?

opposite of dehydration reaction; molecule of water is added to break a covalent bond

T/F Large molecules are disassembled into subunits by hydrolysis reactions

TRUE

What two things do organic molecules contain that inorganic molecules do not?

carbon and hydrogen

What do carbohydrates include?

single sugars (monosaccharides) and molecules of two or more sugar subunits (disaccharides, polysaccharides.)

What type of bond do two monosaccharides create in a dehydration reaction?

covalent

T/F Disaccharides store energy

TRUE

What is a polysaccharide?

sugar molecules bonded together; a type of carbohydrate

What are two main types of polysaccharides?

storage and structural

What is the most common polysaccharide in plants?

starch

What is the most common polysaccharide in humans?

glycogen

What are the differences between starch and glycogen?

starch is found in plants; it needs the enzyme amylase to break down or digest. Glycogen is found in animals and is more densely branched glycogen.

What are the two main classes of structural polysaccharides?

chitin and cellulose

What is chitin?

A polysaccharide that contains nitrogen and acts as the protective shell on crustaceans, crabs and shrimp. (exoskeleton)

What is cellulose?

It's found in plants and is a long chain of linked sugar molecules. It gives plants their structure

What are the three most biologically important types of lipids?

fats, phospholipids and steroids

What is the function of lipids?

energy storage, cell membranes and cell communications

What is fat?

made up of three fatty acids and glycerol

What is a phospholipid?

A liquid containing a phosphate group in its molecule

What is a steroid?

Type of lipid. It has a carbon backbone, and is a four fused ring structure.

What two molecules is fat made of?

Fatty acids and glycerol

T/F Bonds that join fatty acids to glycerol are covalent bonds formed by dehydration reactions.

TRUE

Why do phospholipids spontaneously arrange into a bilayer when added to an aqueous environment?

A cylindrical structure. The head of the structure is hydrophilic while the two tails of saturated and unsaturated fats are hydrophobic. The tails can be shielded in the interior.

T/F A protein is made of chains and amino acids

TRUE

Are steroids lipids?

Yes.

How do amino acids form proteins?

they join by covalent bonds called peptide bonds in a dehydration reaction

Will a protein's confirmation (3D Shape) determine how it will function?

Yes

What is denaturation?

When a protein unravels and loses its normal confirmation. this can happen in response to changes in the physical and chemical conditions in the environment like temperature or pH.

Why does denaturation occur?

Response to changes in physical and chemical conditions in the environment like temperature or pH.

What are the two types of nucleic acids?

DNA, RNA

What is DNA's role in transmission of hereditary info and protein synthesis?

It has genetic material

What is RNA's role in transmission of hereditary info and protein synthesis?

mRNA is to take genetic material off the cytoplasm and tRNA brings amino acids to position on ribosome during construction of a protein.

What are nucleic acids?

Complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain.They are made from nucleotides. (DNA two strands.) (RNA (one strand)

What is the structure of a nucleotide?

PBS; Phosphate group, base, sugar. (deoxyribose in DNA and ribose in RNA.

T/F Organisms are composed of one or more cells.

TRUE

T/F All Cells are surrounded by a plasma membrane, use DNA to store genetic material, contain cytoplasm, and obtain nutrients from their environment

TRUE

What is the plasma membrane's structure?

phospholipid bilayer, proteins, cholesterol

Phospholipid Bilayer

a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic lipid ends facing inward and the hydrophilic phosphate ends facing outward. ... the basic structure of a cell membrane consisting of a double layer of phospholipid molecules. Hydrophilic "heads" and hydrophobic "tails" and they arrange into a double layer when surrounded by water.

What does cholesterol do for the plasma membrane of the cell?

Helps keep its structure

T/F Proteins can have various functions depending on structure. i.e. channel or carrier proteins, transport proteins, receptor proteins and recognition proteins

TRUE

T/F Plasma membranes have selective permeability allowing certain molecules to pass but not others.

TRUE

What are some distinctions of prokaryotic cells?

simple, smaller, lack a nucleus and lack all organelles besides ribosomes

What are some distinctions of eukaryotic cells?

larger, more complex, have a nucleus and membrane-bound organelles

Bacterial and Archaea, Prokaryotic or Eukaryotic?

Prokaryotic

Plant, animal, fungi, protist, prokaryotic or eukaryotic?

Eukaryotic

What is the basic function of the plasma membrane?

decide what can go in and out of the cell (selective permeability)

What do ribosomes do?

they are the protein factories of the cell, manufacturing proteins according to the instructions from the DNA

Describe the structure and basic function of smooth and rough endoplasmic reticulum

they are the manufacturing and packaging systems; SER is a storage for lipids and steroids; RER is a packaging place for proteins

What does the Golgi Apparatus do?

It is the shipping and receiving part of the cell, sorting and altering molecules

T/F Lyosomes are vesicles filled with digestive enzymes to break down old organelles or extra molecules for recycling

TRUE

What do vacuoles do?

Regulate water and store substances

What is a cytoskeleton made of?

It is a network of protein fibers to help maintain the cell shape

What does a cytoskeleton do?

It plays a big role in cell movement, organelle movement and cell division

What is the basic structure and function of cilia and flagella?

They are hair-like structures/ microtubles that move substances or itself around the cell.

What is energy?

Strength and vitality required for activity

What is kinetic energy?

energy that a body possesses while in motion

What is potential energy?

energy possessed by virtue of position, what it has within

What is a reactant?

Reactants (or 'substrates') are the starting materials for a reaction. They are what is changing.

What is a product?

thing that is formed in a reaction

What is the first law of thermodynamics?

energy can neither be created nor destroyed

What is the second law of thermodynamics?

entropy must always increase

What is activation energy?

Energy needed for a reaction to occur

What is the structure of ATP?

3 components: sugar molecule, phosphate group, and base

How is ATP used as energy currency?

It is used on direction by enzymes to build proteins, contract muscles, etc.

How is ATP broken down to form ADP?

it loses the end most phosphate group when instructed to do so by an enzyme and releases energy. (phosphorus cycle)

What is metabolism?

Total of all chemical reactions that occur within a living organism to maintain life

what is a catalyst?

increases the rate of a chemical reaction

what is an enzyme?

substance produced by a living organism that acts as a catalyst to bring about a reaction but does not change during reaction

What is a substrate?

substance on which an enzyme acts

What is an active site?

region on an enzyme that binds to a protein or other substance during a reaction

T/F Enzymes speed up reactions by lowering activation energy

TRUE

What is passive transport?

Diffusion that does not require cellular energy