Test 2 (Cells and what they are made of)

Place the levels of biological organization in the correct order from smallest to largest.

Atoms

Molecule

Cell

Tissue

Organ

Body system

Organism

Population

Community

Ecosystem

Biosphere

Mitochondria

No pigments – opaque/yellow

Mitochondria

Forms ATP

Mitochondria

0.1-1 mM in size (very tiny)

Mitochondria

Use O2 and generate CO2

Mitochondria

Involved in cellular respiration

Mitochondria

Inner membrane forms cristae

Mitochondria

Bean-shaped

Chloroplasts

Involved in photosynthesis

Chloroplasts

Lens-shaped

Chloroplasts

Contains chlorophyll/green

Chloroplasts

1-2 mM in size (small)

Chloroplasts

Use CO2 and generate O2

Chloroplasts

Forms ATP and NADPH

Chloroplasts

Inner membrane forms thylakoid sacs

Both mitochondria and chloroplasts

Provide energy

Both mitochondria and chloroplasts

Contains enzymes and coenzymes

Both mitochondria and chloroplasts

Contains ribosomes

Both mitochondria and chloroplasts

Move freely in the cell

Both mitochondria and chloroplasts

Double membrane bounded organelles

Both mitochondria and chloroplasts

Contains both DNA and RNA

Prokaryotes only

May have a flagella for movement

Prokaryotes only

DNA is circular

Prokaryotes only

Extremely small (1-2 micrometers)

Prokaryotes only

Transcription and translation are NOT separated

Prokaryotes only

Genetic material is concentrated in a nucleoid region

Eukaryotes only

Extensive membrane bound organelles

Eukaryotes only

DNA organized into chromosomes

Eukaryotes only

DNA is contained in a nucleus

Eukaryotes only

Much larger than 1-2 micrometers

Eukaryotes only

Transcription occurs in the nucleus, translation in the cytoplasm

Both prokaryotes and eukaryotes

Contain DNA

Both prokaryotes and eukaryotes

Contain cytoplasm

Both prokaryotes and eukaryotes

Have a cell wall

Both prokaryotes and eukaryotes

Have a cell membrane

Both prokaryotes and eukaryotes

Have ribosomes

Which is true about phospholipids?

. They are amphipathic

. They make up the lipid bilayer of cellular membranes

. They have a polar head and non-polar tails

What causes the hydrophobic tails of lipids to assemble together?

van der Waals forces

True or False: The nuclear envelope is part of the endomembrane system

True

True or False: The smooth endoplasmic reticulum is responsible for the synthesis of 

lipids

True or False: The organelle responsible for modifying newly synthesized proteins is the

Golgi apparatus

Lanel the chemical structure of the amino acid leucine by selecting the correct terms

a carbon

amino group carboxyl group

R group

A molecule of water

Electrons are more likely to be located near the oxygen atom

A molecule of water

the oxygen atom has a slight negative charge

a _________ can occur when a molecule has a hydrogen atom covalently linked to an electronegative atom, whereas _________ occurs between oppositely charged ions, and _________ occurs when atoms share electrons.

A hydrogen bond; an ionic bond; a covalent bond

The shown figure depicts two water molecules joined by three dotted lines. Each dotted line is numbers (1, 2, or 3). Select two numbers that indicate where a hydrogen bond would form between these two water molecules.

2 and 3

Water cohesion results from:

hydrogen bonds

Refer to the shown figure of a simplifies structure of a molecule. Indicate the total number of carbon and hydrogen atoms that this molecule contains by selecting the correct numbers

Total number of carbons: 5, Total number of hydrogens: 12

How many hydrogen atoms are present in a hydrocarbon chain of five carbons joined to each other by single covalent bonds?

12

Which type of fatty acid would be likely to have the lowest melting temperature?

short tails and low saturation

What was the molecules created in Stanley Miller’s experiment?

amino acids

Which molecules did Sutherland and colleagues demonstrate the synthesis of under conditions thought to resemble those of early Earth?

nucleotides

What are the four most common elements in organic molecules?

The four most common elements in organic molecules, in order of decreasing abundance by dry mass, are carbon, oxygen, hydrogen, and nitrogen

What features of carbon allow it to form diverse structures?

Take a close look at Fig. 2.2. How is glucose different from galactose?

Glucose and galactose differ only in the orientation of the -OH and -H groups attached to carbon 4.

What are the essential functions of proteins, nucleic acids, carbohydrates, and lipids?

Proteins act as catalysts to facilitate chemical reactions and also provide structural support of the cell. Nucleic acids encode and transmit genetic information carbohydrates provide a source of energy and make up the cell wall in bacteria, plant, and algae cells. Lipids store energy, act as signaling molecules, and make up the membranes of the cell.

How is diversity achieved in polymers? Use protein ss an example.

Diversity is achieved in polymers through numerous combinations of subunits. A protein, for example, is a polymer of amino acid subunits. As we discuss in Chapter 5, there are 20 different kinds of amino acids. Thus, any combination of subunits can be made, each resulting in a different protein. In this way, polymers are capable of displaying virtually limitless diversity.

What are the basic structure of amino acids, nucleotides, monosaccharides, and fatty acids? Sketch your answers

________ is the backbone of organic molecules.

Carbon

A ________ atom can form up to four covalent bonds with other atoms.

carbon

The geometry of these covalent bonds helps explain the ________ and ________ diversity of organic molecules.

structural, functional

Organic molecules include ______, _______, _______, and _______, each of which is built from simpler units.

proteins, nucleic acids, carbohydrates, and lipids

_________ are linked by covalent bonds to form proteins.

Amino acids

An ___________ consists of a carbon atom (the

α carbon) attached to a carboxyl group, an amino group, a hydrogen atom, and an R group or side chain.

amino acid

The _________ determines the properties of an amino acid.

side chain

nucleotides assemble to form ________, which store and transmit genetic information.

nucleic acids

__________ are composed of a 5-carbon sugar, a nitrogencontaining base, and a phosphate group.

Nucleotides

Nucleotides in ___ incorporate the sugar deoxyribose, and nucleotides in ___ incorporate the sugar ribose.

DNA, RNA

The bases are pyrimidines (_______, _______, and______) and purines (______ and ______) .

(cytosine, thymine, and uracil) and (guanine and adenine)

_______ are carbohydrates, molecules composed of C, H, and O atoms, usually in the ratio 1:2:1, and are a source of energy.

Sugars

_______________ assemble to form disaccharides or longer polymers called complex carbohydrates.

Monosaccharides

______ are hydrophobic

Lipids

_____________ store energy and are made up of glycerol and fatty acids

Triacylglycerols

__________ consist of a linear hydrocarbon chain of variable length with a carboxyl group at one end

Fatty acids

Fatty acids are either _______ (no carbon–carbon double bonds) or _______ one or more carbon–carbon double bonds)

saturated, unsaturated

The _____ packing of fatty acids in lipids is the result of van der Waals forces, a type of weak, noncovalent bond.

tight

Cell Theory

The cell is the fundamental unit of life

Structure of cell membranes

Cell membranes are composed of lipids, proteins, and carbohydrates

Membrane Transport

The cell membrane is a selective barrier that maintains homeostasis by controlling the movement of substances into and out of the cell.

The endomembrane system

The endomembrane system is an interconnected set of membranes in eukaryotes that defines spaces in the cell

Mitochondria and Chloroplasts

Mitochondria and chloroplasts are organelles that harness energy, and likely evolved from free-living prokaryotes.

What are the three basic tenets of the cell theory?

The cell theory states that all organisms are made up of cells, the cell is the fundamental unit of life, and cells come from preexisting cells.

What are the major differences between prokaryotic and eukaryotic cells? Compare their organization, degree of compartmentalization, and relative size

Prokaryotic cells lack a nucleus and extensive internal compartmentalization. Prokaryotic cells are small (usually 1-3 micrometers in diameter or smaller). Because of their small size, they have a large surface-area-to-volume ratio, which means they are able to absorb nutrients from the environment to meet their metabolic needs. Eukaryotic cells have a nucleus and specialized internal structures called organelles. They are 10 times larger in diameter and 1000 times larger in volume than a prokaryotic cell

Which of the answer choices is not considered to be a part of the endomembrane system?

Mitochondria

Most elements of the endomembrane system are connected by:

Vesicular trafficking

Consider a protein that will be released from the cell into the extracellular environment. Where would this protein be located in the endoplasmic reticulum?

in the lumen (inside) of the E.R.

Consider a protein that is targeted to be an integral membrane protein on the surface of a cell. It has a specific functional domain (domain X) facing the external environment of the cell. How will this protein be oriented in the E.R.

It will be embedded in the E.R. Membrane with domain X facing the lumen of the E.R.

Consider a protein that is targeted to be an integral membrane protein on the surface of a cell. It has a specific functional domain (domain Y) facing the cytoplasm of the cell. How will this protein be oriented in the Golgi?

It will be embedded in the Golgi membrane with domain Y facing the cytoplasm of the cell

Many cell functions involve communication between cells via molecular signals that must be sent from one cell to be received by a target cell. Suppose the signal to be sent is a small protein. Where would you expect to find the protein in the Golgi?

It would be in the lumen of the Golgi

The genetic material of a prokaryotic cell is located in its:

nucleoid

Which one of the answer choices is most closely related to Archaea?

eukaryotes

An amphipathic molecule is on that

contains both polar and nonpolar regions

Which lettered part of the space-filling molecular model in the figure represents the hydrophobic portion?

Z

A nuclear pore is most similar to a:

channel protein

What is glycosylation?

the addition of sugars to lipids or proteins

Scientists use which of the answer choices as evidence that mitochondria and chloroplasts had prokaryotic origins?

Both contain their own circular DNA

Which of the answer choices is a pigment associated with chloroplasts and plays a role in energy harvesting?

chlorophyll

Identify all the cell type(s) that belong(s) to each of the listed cellular components in the answer bank. An example of a prokaryotic cell type is bacteria. Examples of eukaryotic cell types include both animal and plant cells.

*practice on paper

Prokaryotes absorb their nutrients from the environment. However, many prokaryotes have cell walls. What can you conclude from this information?

Cell walls are permeable, allowing nutrients to pass through

In order for phospholipids to form bilayers spontaneously in an aqueous environment, the pH should be:

approximately neutral