Chapter 3: The Cell

The Key Term endoplasmic reticulum begins with the prefix endo- which means "in" or "within". Within what part of a cell is the endoplasmic reticulum located?

Around the nucleus.

Where in the cell are the ribosomes?

Attached to the endoplasmic reticulum.

Would a tissue or an organ have more specialized cells? Explain.

A tissue, because the more organs, the more tissues, the more cells.

Enzymes

A type of protein that speeds up a chemical reaction in a living thing.

What is the smallest unit of an element?

An atom.

Lipids

An energy-rich organic compound made up of the elements carbon, hydrogen, and oxygen.

What is carbon dioxide made up of?

Carbon and oxygen.

Which elements are found in living things?

Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

Examples of lipids

Fats, oils, and waxes.

Proteins

Large organic molecules made up of carbon, hydrogen, nitrogen, and in some cases, sulfur. Foods that are high in protein include meat, eggs, fish, nuts, and beans.

What were the names of the three German scientists that made especially important contributions to knowledge about cells?

Matthias Schleiden, Theodor Schwann, and Rudolf Virchow.

What does a microscope enable people to do?

Microscopes enable people to see animals/cells/plants in close-up picture.

Do all plant cells have chloroplasts?

No

Do animals have central vacuoles?

No, but animal cells have smaller storage organelles.

Do animal cells have a cell wall?

No, only plant cells have the cell wall.

Multicellular

Organisms that are composed of many cells.

What types of food contain starch?

Potatoes, pasta, rice, and bread.

What are two ways that cells differ?

Size and shape.

Selectively permeable

Some substances can pass through the membrane, while others cannot.

Compare the functions of the cell wall and the cell membrane in plant and animal cells.

The cell wall helps keep the plant cell's shape and size. The cell membrane on a plant cell or an animal cell prevents bad things from coming into the cell.

Which structure inside the nucleus is involved in this function?

The chromatin.

What kind of microscope did Robert Hooke build?

The compound microscope.

How did the invention of the microscope contribute to knowledge about living things?

The invention of the microscope made it possible for people to discover and learn about cells.

Mitochondria

They convert energy into food molecules. Also known as the "powerhouses".

What is the key function of the nucleus?

To control the cell's activities.

What are the functions of an organism?

To obtain oxygen, get rid of wastes, obtain food, and grow.

What is a water molecule made up of?

Two hydrogen atoms and one oxygen atom.

How many types of nucleic acids?

Two. DNA and RNA.

What is your brain part of?

Your nervous system.

What is diffusion?

Diffusion is the process in which molecules move from an area of higher concentration, to a area of lower concentration.

What is diffusion? What function does diffusion have in the cell?

Diffusion is the process in which molecules move from an area of higher concentration, to an area of lower concentration.

What did Leeuwenhoek look at with his microscope?

Drops of lake water, scrapings from teeth and gums, and water from rain gutters. He found a variety of tiny organisms that he called animalcules, meaning "little animals". Now we call them bacteria.

Oxygen and nitrogen are examples of ........ (Fill in the blanks).

Elements

How are enzymes important to living things?

Enzymes are important to living things because it helps speed up the chemical reactions in cells. Without enzymes, we would die.

Saliva in your mouth is an example of an enzyme because ......................................................................... (Fill in the "blanks").

Enzymes in your saliva speed up the digestion of food in your mouth.

Oxygen molecules enter a cell by diffusion, which is ............................ (Fill in the "blanks").

The process in which molecules move from an area of higher concentration, to an area of lower concentration.

Use diffusion to explain what happens when you drop a sugar cube into a mug of hot tea.

When a sugar cube is dropped into a mug of hot tea, the sugar molecules move away from each other, and "contaminate" the mug with the sugar molecules.

How is active transport different from passive transport?

When cells use active transport, the cell is using its own energy, while in passive transport, the cell is not using any of its own energy.

Water is an example of a compound, which is .................................... (Fill in the "blanks").

When two or more elements combine chemically.

What is a compound?

When two or more elements combine chemically.

Does the cell theory hold true for all living things, big or small?

Yes

Is the cytoplasm always moving?

Yes

How do you describe the structure of an object?

You describe what it is made of and how its parts are put together.

Chloroplasts

Capture energy from sunlight and use it to produce food. They make leaves green. Root cells do not have chloroplasts because they live underground, and don't have accessibility to sunlight, and they don't need it.

Which of the four types of organic compounds serve as an energy source for cells?

Carbohydrates is an organic compound that serves as an energy source for cells. It is organic because it contains carbon.

An organic compound contains only the elements carbon, hydrogen, and oxygen. Could this compound be a carbohydrate? Could it be a protein?

Carbohydrates only contain the elements carbon, hydrogen, and oxygen. Since it has the element carbon, it is an organic compound.

What are the sizes of cells?

Cells are so small that they are measured in units are called micrometers. One micrometer is one millionth of a meter.

What do cells in your digestive system do?

Cells in your digestive system absorb food. This food provides your body with energy and materials needed for growth.

What are those "strands" floating directly ahead in the nucleus?

Chromatin, which contain genetic material, the instructions for directing the cell's functions.

The nucleus can direct the cell's activities because it contains ......... (Fill in the "blanks").

Chromatin.

Explain the difference between elements and compounds.

Compounds are when elements are combined, not elements themselves.

The process by which water moves across a cell membrane is called: a. osmosis b. active transport c. organelle d. resolution

a. osmosis

In plant and animal cells, the control center of the cell is the: a. chloroplasts b. lysosomes c. nucleus d. Golgi body

c. nucleus

Starch is an example of a: a. nucleic acid b. protein c. lipid d. carbohydrate

d. carbohydrate

All living things are composed of: a. blood b. chloroplasts c. vacuoles d. cells

d. cells

A storage compartment of the cell is the: a. cell wall b. lysosome c. endoplasmic reticulum d. vacuole

d. vacuole

What shape is the nucleus?

A large, oval structure.

Describe the characteristics of the endoplasmic reticulum.

A maze of passageways that help form proteins and other materials. They also carry material throughout the cell.

What could you compare the cell membrane to?

A window screen.

How do multicellular organisms differ from unicellular organisms?

Because multicellular organisms are consisted of more than one cell, and unicellular organisms are consisted of only one cell.

How many cells do organisms have?

From one, to trillions.

Describe how water molecules move through the cell membrane during osmosis.

Inn osmosis, water molecules move by diffusion from an area where they are highly concentrated through the cell membrane to an area where they are less concentrated.

What kind of genetic information is in the chromatin?

Instructions for growing and reproducing.

What role did the microscope play in the development of the cell theory?

The microscope played a very important role in the development of the cell theory because without microscopes, we wouldn't be able to see cells.

How can materials get through into the nucleus?

The nuclear envelope has little pores that materials can get through.

How many cells are in one square centimeter of your skin's surface?

More than 100,000 cells.

What is the relationship among cells, tissues, and organs?

Organs are made up of tissues, which are made up of cells.

Suppose a dye for staining cells stains the region where ribosomes are made. What would you expect to see inside the cell's nucleus?

The nucleolus.

Use Virchow's ideas to explain why plastic plants are not alive.

Plastic plants are not made up of cells in the first place. If cells came up from nowhere, then plastic plants would be alive. Plastic, alone, would be alive.

Which of the four types of organic molecules contain the element nitrogen?

Proteins contain the element nitrogen.

Which three people helped create the cell theory?

Schleiden, Schwann, and Virchow.

Which organelles might you expect to see in large quantities in cells that actively release proteins outside the cell?

The Golgi bodies.

Suppose a cell is seriously deprived of water. How might this lack of water affect the cell's enzymes? Explain.

The cell's enzymes would be affected by lack of water because most chemical reactions could not take place without water. Enzymes help speed up a chemical reaction in a living thing. Without water, the chemical reactions take too slow, or not take place at all.

What is osmosis?

The diffusion of water molecules through a selectively permeable membrane.

Describe the function of the cell wall.

The function of the cell wall is to keep the plant cell's size and shape. It also keeps bad things out of the cell.

How are the functions of ribosomes, Golgi bodies, and the endoplasmic reticulum related?

The ribosomes produce proteins, ship it through the endoplasmic reticulum, who give it to the Golgi bodies, which distribute it to other parts of the cell. All three of them have to do with proteins.

Identify the functions of ribosomes and Golgi bodies.

The ribosomes produce proteins. The Golgi bodies receive those proteins, package them up, and distribute them to other parts of the cell.

What do a fungus, a tree, and a red newt have in common?

They are all living things, or organisms. And, like all organisms, they are made of cells.

What do a bird's feather, a spider's web, and your fingernail have in common?

They are made mainly of proteins.

Mitochondria are "powerhouses" of the cell because ....................................................... (Fill in the "blanks").

They convert energy into food.

What are transport proteins?

Transport proteins are like little guards that carry molecules into the cell using the cell's energy.

Explain why transport proteins require energy to function in active transport.

Transport proteins require energy to function in active transport because in active transport, the transport proteins are "carrying" the molecules in the opposite direction that the other molecules are moving.

What did Virchow contribute to the cell theory?

Virchow contributed to the 3rd statement of the cells theory (that all cells are made up of other cells) because he proved that that was true.

What three important functions does water perform in cells?

Water helps dissolve chemicals needed in cells, it helps keep the cell's size and shape, and it helps keep the cell at a steady temperature.

What is one inorganic compound vital for chemical reactions in cells? What are four groups of organic compounds important to living things?

Water is one inorganic compound vital for chemical reactions in cells because it is made up of two atoms of hydrogen, and one atom of oxygen. Therefore, it does not contain carbon, making it inorganic. Four groups of organic compounds important to living things are carbohydrates, lipids, proteins, and nucleic acids. All four of them contain carbon, making them organic.

A selectively permeable membrane separates solutions A and B. The concentration of water molecules in Solution B is higher that that in Solution A. Describe how the water molecules will move.

Water molecules will move by using osmosis because the water molecules will move from Solution B to Solution A.

What role do the cell wall and cell membrane play in the cell?

A cell wall helps to protect and support the cell. The cell membrane controls what substances come into and out of a cell.

Organ System

A group of organs that work together to perform a major function.

Tissue

A group of similar cells that work together to perform a specific function.

What is the smallest unit of many compounds?

A molecule. A molecule of carbon dioxide consists of one carbon atom and two oxygen atoms.

Cytoskeleton

A protein "framework" inside the cell that gives the cells their shape. Animal cells have this instead of cells walls.

Cell Wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms. The animal cells does not have a cell wall. Instead, it has the cytoskeleton.

What is the cell wall mostly made of?

A strong material called cellulose. Although the cell wall is tough, many materials, including water and oxygen, can pass through easily.

How many common types of amino acids are there?

About 20, but cells can combine them in different ways to form thousands of different proteins.

What can scientists learn about cells now from the third cell theory?

About the organism's growth and reproduction.

What is the difference between passive transport and active transport?

Active transport requires the cell to use its own energy, while passive transport does not.

What are elements and compounds?

An element is any substance that cannot be broken down into simpler substances. When two or more elements combine chemically, they form a compound.

Carbohydrates

An energy-rich organic compound made up of the elements carbon, hydrogen, and oxygen. Sugars and starches and examples of carbohydrates.

Why are cells so small?

As a cell's size increases, more of its cytoplasm is located farther from the cell membrane. Once a molecule enters a cell, it is carried to its destination by a stream of moving cytoplasm. But in a larger cell, the streams of cytoplasm must travel farther to bring materials to all parts of the cell. It would starve.

Why would Hooke's discovery have been impossible without a microscope?

Because a microscope can let you see things that your naked eye can not see. Such as paper shavings.

Why is osmosis important to cells?

Because cells cannot function properly without adequate water, many cellular processes depend on osmosis

How are the structure of living things determined?

By the variety of ways in which living things are put together.

What are cells?

Cells are basic units of structure and function in living things. This means that they form the parts of an organism and carry out all of an organism's processes, or functions.

What are Hooke's observations of the cork under his microscope?

Cork, the bark of the cork tree, is made up of cells that are no longer alive. To Hooke, the empty spaces in the cork looked like tiny rectangular rooms. Therefore, Hooke called the empty spaces cells, which is a word meaning, "small rooms". Hooke described his observations this way: "These pores, or cells, were not very deep, but consisted of a great many little boxes...."

How do most small molecules cross the cell membrane?

Diffusion is the main method by which small molecules move across the cell membrane.

What are the three methods that substances can move into and out of a cell?

Diffusion, osmosis, or active transport.

Organic compounds

Do contain the element carbon.

Inorganic compounds

Do not contain the element carbon.

Cell Membrane

Forms the outside boundary that separates the cell from its environment. The cell membrane in a plant cell is located inside of the cell wall.

When did Hooke make his compound microscope?

In 1660.

When did Leeuwenhoek make his simple microscope?

In 1674. The simple microscope could magnify up to 266 times.

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

In addition to providing energy for the cell, carbohydrates are important components of some cell parts. In addition do their functions as an energy source, lipids also make up most of the cell membrane. The proteins known as enzymes perform important functions in the chemical reactions that take place in cells. Nucleic acids contain the instructions that cells need to carry out all the functions of life.

How are the cells of multicellular organisms organized?

In multicellular organisms, cells are often organized into tissues, organs, and organ systems.

What organelles are found in the cytoplasm and what are their functions?

In the cytoplasm are many organelles, including mitochondria, endoplasmic reticulum, ribosomes, Golgi bodies, chloroplasts, vacuoles, and lysosomes. Each of these organelles has specific functions in the cell.

Where are the ribosomes made?

In the nucleolus (in the nucleus).

Organ

Is made up of different kinds of tissues that work together. For example, your brain is made up of different kinds of tissues.

What types of functions does water do in cells?

It dissolve chemicals that cells need, it help cells keep their shape, and it help keep a steady temperature in cells.

Explain this statement: Cells are the basic units of structure and function in organisms.

It means that if we didn't have cells, we wouldn't be able to do anything, such as seeing, digesting, any of that. Cells are the most basic thing to what organisms are made of. We cant get any simpler than cells!

How is water important to the function of cells?

Most chemical reactions within cells could not take place without water.

Animals have many cells. Therefore, animals are ............. organisms. (Fill in the "blanks")

Multicellular

Transport proteins

One method is that transport proteins in the cell membrane "pick up" molecules outside the cell and carry them in, using energy. Transport proteins also carry molecules out of cells in a similar way. Some substances that are carried into and out of cells in this way include calcium, potassium, and sodium.

Unicellular

Organisms that are composed of one cell. An example of a unicellular organism would be bacteria. Bacteria is the most numerous organism on Earth.

What kinds of materials must the cell membrane let into the cell?

Oxygen and food molecules. But waste materials must move out of cells. Oxygen, food molecules, waste products, and many useful cell products must pass through the cell membrane.

What are the three gases in the air?

Oxygen, nitrogen, and carbon dioxide.

What do proteins form/create?

Parts of the cell membrane, and many of the organelles within the cell.

Endoplasmic Reticulum

Passageways that help form proteins and other materials.

RNA

Plays an important role in the production of proteins. RNA is found in the cytoplasm as well as in the nucleus. Also known as Ribonucleic acid.

Ribosomes

Produce proteins. Also known as "factories".

Amino acids

Protein molecules that are made up of smaller molecules called amino acids.

Golgi bodies

Receive proteins and other newly formed materials from the endoplasmic reticulum. They then package and distribute materials to other parts of the cell. Also known as the "post office".

Who were the two early contributors to the understanding of cells?

Robert Hooke and Anton van Leeuwenhoek. They both built their own microscopes.

Who was one of the first people to see cells?

Robert Hooke, an English scientist and inventor.

In what important function are the cells in your eyes involved?

Seeing, processing pictures.

What are some of the differences and similarities of an animal cell and a plant cell?

Similarities: Nucleus, nucleolus, cytoplasm, ribosomes, endoplasmic reticulum, Golgi body, cell membrane, vacuole, and the mitochondria. Differences (animal): Lysosomes, cytoskeleton, and the not-as-central vacuoles. Differences (plant): Cell wall, chloroplasts, and a central vacuole.

What kind of microscope did Anton van Leeuwenhoek build?

Simple microscopes.

Lysosomes

Small, round structures containing chemicals that break down certain materials in the cell. They also break down old cell parts and release the substances so they can be used again. Also known as the "cleanup crew".

Are elements and compounds larger or smaller than cells and organelles?

Smaller

Vacuole

Store food and other materials needed by the cell. They can also store waste products. Also known as the "storage areas".

Define "structure" and "function".

Structure= The way that an organism/cell is put together as a whole. Function= The process that enables an organism/cell to survive.

What did Schwann figure out in 1839 about animals?

That all animals are made up of cells. He also concluded that all living things were made up of cells.

What did Schleiden figure out in 1838 about plants?

That all plants are made up of cells.

What did Virchow figure out in 1855 about where cells came from?

That new cells are formed only from cells that already exist.

When were microscopes invented?

The 1st microscope was invented in 1590.

What is the cell theory?

The cell theory states the following: 1. All living things are composed of cells. 2. Cells are the basic units of structure and function in living things. 3. All cells are produced from other cells.

Summarize Hooke's observations of cork under a microscope.

The cork was made up of dead cells. These empty spaces, Hooke called cells, meaning "small rooms". The cells were not very deep, but consisted of a great amount of many little boxes.

Osmosis

The diffusion of water molecules through a selectively permeable membrane.

DNA

The genetic material that carries information about an organism and is passed from parent to offspring. The information in DNA is also used to direct all of the cell's functions. Also known as Deoxyribonucleic acid.

What protects the nucleus from harm?

The nuclear envelope.

What is the role of the nucleus in the cell?

The nucleus is the cell's control center, directing all of the cell's activities.

Diffusion

The process by which molecules move from an area of higher concentration to an area of lower concentration. The concentration of a substance is the amount of the substance in a given volume.

Cytoplasm

The region between the cell membrane and the nucleus. Also known as the "soup".

How do cells differ?

The variety of structure in cells reflects differences in cell functions.

Organelle

They carry out specific functions within the cell. They are also the different parts of the cell.

What do red blood cells do?

They carry oxygen throughout your body. Their flattened shape enables them to fit through tiny blood vessels.

What do the extensions on the nerve cell do?

They help transmit information from one part of your body to another.

Because bacteria each have only one cell, they are ........... organisms. (Fill in the "blanks")

Unicellular

Nucleic acids

Very long organic molecules made of carbon, oxygen, hydrogen, nitrogen, and phosphorus.

What is an example of an inorganic compound?

Water, sodium, chloride, and table salt.

What causes diffusion?

When molecules move, they bump into each other. When they do this, they push away from each other. Over time, the molecules of a substance will continue to spread out.

Complex carbohydrates

When sugar molecules combine forming large molecules.

Is water a compound?

Yes