how animals work all chapters

At the gym one day, you notice a new energy bar being sold that advertises quick energy for your workout. To impress you further, it is claimed that this bar contains only carbon, oxygen, and hydrogen atoms. What kind of biological molecule(s) would you be eating if you ate this energy bar?

Carbohydrates and lipids

What is the difference between simple sugars and complex carbohydrates?

Complex carbohydrates are polymers of simple sugars.

What can Carbohydrates function as?

a source of energy or can function as an extremely durable structural material, depending on the specific nature of the chemical bonds between subunits (monomers)

what is The quaternary level of protein structure

a functional (biologically active) complex of two or more three-dimensional proteins (e.g., hemoglobin)

What is the difference between simple sugars and complex carbohydrates?

Complex carbohydrates are polymers of simple sugars.

A nucleotide is composed of

a sugar, a phosphate group, and a nitrogen-containing base

A characteristic of the carbon atom that contributes to its ability to form an immense diversity of organic molecules is its

ability to covalently bond with up to 4 other atoms

If a lipid is completely saturated, would you predict it to be liquid or solid at room temperature?

solid

The general formula for carbohydrates is a ratio of carbon to hydrogen to oxygen expressed as

1:2:1

Amino acids and polypeptides are found in

proteins

Glycerol and fatty acids are components of

triglycerides, a type of lipid

Proteins are polymers of the monomers

amino acids

Which of the following choices does not properly pair an organic compound with one of its building blocks (subunits)?

Polysaccharide-monosaccharide

Fat-fatty acid

Protein-amino acid

Nucleic acid-glycerol

Nucleic acid-glycerol

How are humans able to use the energy in the starch of a potato but not in the cellulose of celery?

Our bodies cannot break the bonds in cellulose but can break those in starch.

During the process of polymerization (synthesis of biological polymers), water is __________, and the reaction is consequently called a __________ reaction.

removed; dehydration

Phospholipids contain a "head group" that is __________ and two fatty acid "tails" that are __________.

hydrophilic; hydrophobic

A scientist is studying the metabolism of proteins in yeast and wants to follow the formation of proteins from the earliest possible point. In her experiment, she will feed the yeast radioactive nutrients and follow the fate of the radioactivity in the cells. Which of the following atoms will allow her to exclusively follow proteins in the cell?

radioactive sulfur

Fat accumulates in our bodies when we overeat. This is because __________.

lipids are a form of long-term energy storage

The earliest ancient Egyptians buried their dead in pits in the desert. The heat and dryness of the sand dehydrated the bodies relatively quickly, leaving lifelike mummies. The trunk region of the body dehydrates much more slowly than peripheral regions such as the hands or feet. which regions of a mummy's body would give the most intact pieces of DNA?

fingers

How are large organic molecules (macromolecules) synthesized?

By dehydration reactions utilizing monomers

Which of the following functional groups would you expect to help make an organic molecule soluble in water?

A carbon backbone with many hydroxyl groups, OH

A characteristic of the carbon atom that contributes to its ability to form an immense diversity of organic molecules is its __________.

ability to covalently bond with up to 4 other atoms

Complex carbohydrates have numerous roles in plant cells, including __________.

long-term energy storage and as an important structural material for plant cell walls

Which type(s) of organic molecules contain a phosphate functional group?

Both nucleic acids and phospholipids

The three natural processes that form the basis for evolution are __________.

genetic variation, inheritance, and natural selection

Which scientist(s) is/are credited with developing the theory of evolution in the mid-1800s?

Both Charles Darwin and Alfred Russel Wallace

The process of evolution involves __________.

natural selection of organisms that produce more offspring under certain environmental conditions

Natural selection would be best illustrated by which of the following?

A bacterial cell in the human body with a genetic variation that allows it to survive when the person takes antibiotics

A bacterial cell in the human body that mutates itself when a person takes antibiotics

A bacterial cell that has a spontaneous mutation.

A bacterial cell in the human body that dies when a person takes antibiotics

Natural selection would be best illustrated by which of the following?

A scientist examines an organism and finds that it is able to grow, maintain complexity, and acquire and use materials and energy. The scientist declares that this organism is a living thing. Are they correct?

No, a living thing must be able to also respond to stimuli, reproduce, and evolve.

Why is a control needed in an experiment?

to provide a comparison with the experimental results obtained when changing the variable

A fundamental characteristic of life on Earth is that __________.

living things grow and reproduce

The ability of an organism to maintain its internal environment within the limits required to sustain life is called __________.

homeostasis

All of the following characteristics define life except __________.

the ability to infect other organisms

Experiments are carefully designed in an attempt to __________.

The diversity of life is mainly due to __________.

natural selection and variable environments

Energy from the sun can be captured by living organisms through a process called __________.

photosynthesis

Experiments are carefully designed in an attempt to __________.

test a single experimental variable

Simple experiments generally isolate and test one __________ at a time.

variable

The organic complexity and organization of living organisms depends on the periodic capture of raw materials and energy. Ultimately, the source of this energy is __________.

the sun

Maintaining the complexity of living organisms __________.

requires energy

The difference between smooth ER (SER) and rough ER (RER) is __________.

the presence of ribosomes on RER

Why are living cells limited to remaining microscopic in size?

Exchanges of substances at the membrane surface would take too long to diffuse throughout the interior of the cell.

Which organelles are found in animal cells, but are absent in most plant cells?

Centrioles

Lysosomes contain very powerful digestive enzymes that can break down proteins, carbohydrates, and other molecules. Why don't these enzymes digest the cell itself?

The enzymes are separated from the cytoplasm by the lysosomal membrane.

Which organelles are part of the endomembrane system of eukaryotic cells?

Endoplasmic reticulum, Golgi apparatus, and lysosomes

The endoplasmic reticulum is needed for the __________.

synthesis of proteins and lipids

Prokaryotic cells do not contain __________.

endoplasmic reticulum

Which of the following is not true of the cytoskeleton?

• it positions and moves cell parts

• It gives shape and support to the cell

  It is composed of different types of proteins

• It is used in cell recognition

It is used in cell recognition

A researcher has discovered an unusual organism deep in the crust of the Earth. She wants to know whether it is prokaryotic or eukaryotic. Imagine that she has rapid tests to determine whether the following molecules are present: DNA, RNA, phospholipids, and the presence of multiple chromosomes and associated proteins. Which test would you advise her to use and why?

Test for the presence of multiple chromosomes and associated proteins, because only eukaryotes have multiple chromosomes.

In certain types of genetic engineering, DNA is injected into the nucleus of a recipient animal cell. What is the lowest number of membranes that must be pierced by the microscopic needle in order to inject the DNA? (Note that the needles used are not small enough to pass through a nuclear pore.)

3

Sorting and modification of proteins is an important function of __________.

the Golgi apparatus

What is the correct order in which newly synthesized proteins are delivered to the plasma membrane?

They are delivered from the endoplasmic reticulum to the Golgi apparatus to the plasma membrane.

How do molecules such as proteins and RNA enter into or exit from the nucleus?

Molecules move through pores in the nuclear envelope.

Imagine that you are late for an appointment and you reach the office door out of breath because you just ran the last three blocks from the bus stop. Which of the following descriptions of what oxygen is used for in your cells is correct?

The mitochondria in my muscle cells need this extra oxygen to break down sugars and produce the energy I need to run.

Which of the following structures is/are found in all cells?

Plasma membrane

The cell theory states that __________.

all living things are composed of cells

Which of the following originated by endosymbiosis?

Both chloroplasts and mitochondria

Where are proteins that are going to be exported from the cell synthesized?

On the rough endoplasmic reticulum

What do we call the fluid in which all cellular organelles are suspended?

Cytosol

The function of the mitochondria is __________.

to convert energy from food molecules to high-energy bonds in ATP

Plasmids are located where

in the cytoplasm

Chromosomes consist of __________.

proteins and DNA

Which organelle would you expect to be in abundance in the liver of a drug addict?

The smooth endoplasmic reticulum

Which of the following contain ribosomes?

Plant cells, animal cells, bacterial cells, and chloroplasts

Substances are able to cross the lipid bilayer of a cell at different rates that are unique for each substance. Which of the following characteristics would favor the simple diffusion of a substance across a cell membrane?

Small molecule size

Which two forms of cell attachments provide pathways between adjacent cells?

Gap junctions and plasmodesmata

Exocytosis is the reverse of which process?

Pinocytosis and receptor-mediated endocytosis

White blood cells are attracted to the site of an inflammation. How do they begin to destroy invading bacteria?

Through phagocytosis and the digestion of the bacteria

The concentration of sodium ions is lower in the cytoplasm of a heart muscle cell than it is in the extracellular fluid. By what mechanism does the cell maintain this difference?

Active transport

Where is interstitial fluid found?

Outside the cell

What is an aquaporin?

A plasma membrane protein that contains channels used to move water through the membrane in response to osmotic pressure.

Which type of cell would you expect to burst when placed in a hypotonic solution?

Red blood cell

Why do phospholipids form a hydrophobic region in the plasma membrane?

Fatty acid tails on the phospholipids cannot form hydrogen bonds with water and orient themselves together, forming a bilayer.

Which form of energy requiring transport is used to remove whole cells, or major parts of cells, from the interstitial fluid?

Phagocytosis

How does water pass through a plasma membrane if the center of the structure is hydrophobic?

The random movement of water carries some through the membrane, while transport proteins handle the rest.

Is the cytosol fluid of animal cells hypotonic, hypertonic, or isotonic to the interstitial fluid surrounding them?

Isotonic

Which type of membrane protein is used to generate and maintain concentration gradients?

Transport protein

Which form of energy-requiring transport is used to acquire material in the same concentration as in the interstitial fluid?

Pinocytosis

Which form of passive or active transport functionally limits the maximum size that any cell can achieve?

Diffusion

What is an example of the actions of enzymes at membrane surfaces?

Complete carbohydrate and protein digestion in the small intestine.

How does a plant organelle help to create turgor pressure?

The fluid in central vacuoles is maintained hypertonic to the cytoplasm of the cell, so excess water in the cell enters to vacuole, forming the turgor pressure.

Both facilitated diffusion and receptor-mediated endocytosis require the use of plasma-membrane proteins. What is different about these processes?

Receptor-mediated endocytosis requires the use of energy, while facilitated diffusion does not.

Match the type of membrane transport associated with each of the following: oxygen, glucose, chloride ions, water.

Oxygen = simple diffusion, glucose = facilitated diffusion through carrier proteins, chloride ions = facilitated diffusion through channel proteins, water = osmosis

Where does ATP attach in the process of active transport?

To the inside membrane of the active transport membrane protein

Glycoproteins are a combination of __________.

carbohydrates (glycol-) and proteins

Which of the following associations is not correct?

Plasmodesmata–allow communication between plant cells

Gap junctions–allow communication between animal cells

Desmosomes–allow inflexible attachments among cells

Tight junctions–create watertight junctions between cells

Desmosomes–allow inflexible attachments among cells

How does a messenger molecule, which stays in the interstitial fluid, cause a response in a cell?

The messenger molecule binds to a receptor protein, which becomes activated and a response in the cell occurs.

Cholesterol levels can be a health hazard in human beings, yet cholesterol is an important component of plasma membranes. Why?

Interactions between cholesterol and phospholipids help to stabilize the membrane during temperature fluctuations.

Many metabolic poisons work by inhibiting ATP production. Which type of transport would be most affected?

Active transport

White blood cells are attracted to the site of an inflammation. How do they begin to destroy invading bacteria?

Through phagocytosis and the digestion of the bacteria

If all matter tends toward increasing randomness and disorder, how can life exist on Earth?

There is a constant input of energy from the sun.

The second law of thermodynamics states that __________.

disorder tends to increase over time