Bio 10 Exam 1

Osmosis can be defined as ________.

the diffusion of water across a selectively permeable membrane

Why is water considered a polar molecule?

the oxygen end of the molecule has a slight negative charge and the hydrogen end has a slight positive charge.

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.

transport proteins; down

A fatty acid containing one or more double bonds is called______ and is __________ at room temperature?

unsaturated & Liquid

Relative to other substances, water tends to resist changes in temperature. Why?

water is highly cohesive

A dehydration reaction is the process in which __________.

water molecules are formed when polymers are synthesized from monomers

Which of these refers to atoms with the same atomic number but different atomic masses?

isotopes

As water freezes, ________.

its molecules move farther apart

example of protein

lactase

Steroids are in the class of molecules we call?

lipids

An animal cell placed in a hypertonic solution will __________.

lose water by osmosis and shrivel

what breaks down worn out organelles?

lysosomes

What carries instructions for making proteins from the nucleus into the cytoplasm?

mRNA

what are hollow rods that shape and support the cell

microtubules

Where in a cell is ATP made?

mitochondria

if placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference?

relative inelasticity and strength of the plant cell wall

One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by?

ribosomes

_____ are the sites of protein synthesis.

ribosomes

what type of fat only contain single bonds in their fatty acid tails?

saturated fat

Where is calcium stored?

smooth endoplasmic reticulum

Where are lipids made in the cell?

smooth endoplasmic reticulum (ER)

Example of carbohydrates

starch

Some tiny insects are able to walk on water. Why?

surface tension

Water is sometimes called the "universal solvent." Is that accurate?

For the most part. Water readily dissolves most substances, but not hydrophobic ones.

What modifies and packages proteins?

Golgi apparatus

what converts chemical fuel into ATP packets that can power the cell?

Mitochondrion

In order to have a positive charge, an atom must have______.

More protons than electrons

Isotopes of an element have the same number of _______ and different numbers of ________.

Protons and Neutrons

_________is used in all steps of protein synthesis and carries the genetic information of many viruses.

RNA

In salt, what is the nature of the bond between sodium and chlorine?

ionic

What is the term for an atom that is electrically charged as a result of gaining or losing electrons?

ions

what is the ideal osmotic environment for an animal cell?

isotonic environment

what type of solution will cause a plant cell to be flaccid (limp)?

isotonic solution

Which term is used to describe an animal's ability to survive if the cells are exposed to a hypotonic or hypertonic environment?

osmoregulation

A polypeptide is a long chain of amino acids bonded together by __________.

peptide bonds

what has a strong protective structure made from cellulose fibers?

plant cell wall

Both animal and plant cells accumulate water through osmosis when placed in hypotonic solutions. This causes the cells to swell. Why can plant cells better tolerate this?

plant cells have rigid cell walls that limit how far cells expand & prevent them from bursting

The _____ is a selective barrier, regulating the passage of material into and out of the cell.

plasma membrane

how are charges distributed on a water molecule?

The oxygen end is negative relative to the end with the two hydrogen atoms.

Water readily sticks to many other substances, a property called ______.

adhesion

Proteins are polymers constructed from ______ monomers?

amino acid

The building blocks of proteins are called __________.

amino acids

The simplest unit of matter that still retains the properties of an element is __________.

an atom

An ionic bond involves _____.

an attraction between ions of opposite charge

Atoms with the same number of protons but with different electrical charges _____.

are different ions

_____ is/are identical in structure to centrioles.

basal bodies

A substance that resists changes in pH is referred to as a(n) _____.

buffer

The large diversity of biological molecules depends on atoms of the element __________.

carbon

Plant cell walls consist mainly of __________.

cellulose

what regulates cell composition, creates internal pressure, and stores cell compounds?

central vacuole

What reaction links polymers to monomers?

dehydration reaction

The passive movement of molecules from an area of higher concentration to an area of lower concentration is called __________

diffusion

All lipids share this characteristic.

do not dissolve in water

Substances that cannot be broken down into other substances are called __________.

elements

lactase is an_____.

enzyme

Cells with a higher concentration of ions than the surrounding medium tend to ________.

expand

What is the main sugar used by cells for energy?

glucose

In the reaction glucose + fructose → sucrose + water, __________ is a reactant and __________ is a product.

glucose and water

Hydrocarbons are organic molecules that contain only __________.

hydrogen and carbon atoms

In osmosis, water moves across a selectively permeable membrane toward the __________ solution; that is, toward the solution with the __________ solute concentration.

hypertonic ... greater

in what type of solution will a plant cell lose water a plasmolyze?

hypertonic solution

what is the ideal environment for a plant cell?

hypotonic environment

what type of solution causes an animal cell to gain water, swell, and possibly burst?

hypotonic solution

What is the structure of a steroid?

-5 benzene rings -1 pentene ring

Relative to a pH of 7, a pH of 4 has a ________.

1,000 times higher H+ concentration

A single carbon atom can form a maximum of ________ covalent bond(s).

4

a single carbon atom can form a maximum of __________ covalent bonds.

4 covalent bonds

What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?

6

What is the pH inside most living cells?

7

An uncharged atom of mercury has an atomic number of 80 and an atomic mass of 200. This atom has ________ protons, _______ neutrons, and _________ electrons.

80, 120, 80

What name is given to bonds that involve the sharing of electrons?

Covalent Bonds

__________is the self-replicating material present in nearly all living organisms; it is the main constituent of chromosomes and the carrier of genetic information.

DNA

example of nucleic acid

DNA and RNA

Why is water polar?

Uneven distributions of charges

what makes food by converting light energy to chemical energy?

chloroplasts

Example of lipids

cholesterol

The _____ is composed of DNA and protein.

chromatin

___________are tightly coiled bundles of DNA and protein found in the nucleus of most living cells.

chromosomes

The tendency of water molecules to stick together is called __________.

cohesion

Water striders are common insects that can skip across the surface of ponds and streams. This lifestyle is enabled by water's _____.

cohesion and resulting surface tension

Substances that contain two or more elements in a fixed ratio are called __________.

compounds

Which of these is a type of chemical bond that involves the sharing of electrons?

covalent bond

The structural framework in a cell is the

cytoskeleton

What name is given to this reaction: galactose + glucose ---> lactose + water?

dehydration

The lower the pH of a solution, the ________.

more acidic the solution

what pH does a solution have when the OH and H ions are equal?

neutral

Carbon-12 and carbon-13 are different in the number of __________ they have.

neutrons

_________s the two-layered membrane that encases the nucleus of a eukaryotic cell, separating the nucleus from the cytoplasm.

nuclear envelope

A protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm is called a________.

nuclear pore

Ribosomal subunits are manufactured by the _____.

nucleolus

The round body that sits inside the nucleus of a eukaryotic cell and makes ribosomal subunits from proteins and ribosomal RNA is known as the__________.

nucleolus

The building blocks of nucleic acid molecules are called __________.

nucleotides

Where is the genetic information of the cell stored?

nucleus

_________is the most prominent membrane-bound organelle in eukaryotic cells, and it houses most of a cell's DNA.

nucleus

In an atom with a neutral overall charge, the number of protons is equal to the __________.

number of electrons