Name ______Period ____
Inside Cells Worksheet Packet
Can you identify the cell structures mentioned in these riddles?
1. I’m a real “powerhouse”6. I’m a series of tubes
That’s plain to see. Found throughout the cell.
I break down food I transport proteins
To release energy. And other things as well.
What am I? ______What am I? ______
2. I’m strong and stiff7. I’m full of holes
Getting through me is tough. Flexible and thin.
I’m found only in plants I control what gets out
But I guess that’s enough. As well as what comes in.
What am I? ______What am I? ______
3. My name means “colored bodies”8. Proteins are made here
And I contain DNA. Even though I’m quite small.
I pass on traits though genes You can find me in the cytoplasm
In a systematic way. Or attached to E.R.’s wall.
What am I? ______What am I? ______
4. I’m the “brain” of the cell9. I’ve been called a “storage tank”
Or so they say. By those with little taste.
I regulate activities I’m a sac filled with water,
From day to day. Food, enzymes, or waste.
What am I? ______What am I? ______
5. Found only in plant cells10. Since I contain many enzymes
I’m as green as can be. I can digest an injured cell.
I make food for the plant And can break down a large molecule
Using the sun’s energy. Into a smaller one as well.
What am I? ______What am I? ______
Communication Activity
Instructions: Read through these paragraphs once, then read the questions that follow. Re-read the paragraphs again, and write answers to the questions below.
Poisons, Antibiotics, and Cells
The life of a cell is dependent on a rich soup of enzymes that float in the cell's cytoplasm. Many different poisons work by disrupting the balance of the soup in one way or another.
For example, diphtheria bacteria work by injecting a toxin into a host cell. This toxin gums up the action of the host cells’ ribosomes, making it impossible for the ribosome to make proteins. The toxin in a death-cap mushroom, on the other hand, gums up the “copying” of DNA. In both cases, the production of new enzymes shuts down and the cells affected by the toxin can no longer grow or reproduce.
An antibiotic is a poison that works to destroy bacterial cells while leaving human cells unharmed. All antibiotics take advantage of the fact that there are many differences between bacterial cells and human cells. If a toxin is found, for example, that affects an E. coli ribosome but leaves human ribosomes unharmed, then it may be an effective antibiotic. Streptomycin is an example of an antibiotic that works in this way – you may have taken some of you had strep throat or scarlet fever.
Penicillin was one of the first antibiotics. It gums up a bacterium's ability to build cell walls. Since bacterial cell walls and human cell membranes are very different, penicillin has a big effect on certain species of bacteria but no effect on human cells. The sulfa drugs, another kind of antibiotic, work by disabling an enzyme that creates protein bases in bacteria but not in humans. Without these bases, the bacteria cannot reproduce.
You can see that the search for new antibiotics occurs down at the enzyme level, hunting for differences between the enzymes in human and bacterial cells that can be exploited to kill bacteria without affecting human cells.
The unfortunate problem with any antibiotic is that it becomes ineffective over time. Bacteria reproduce so quickly that the probability for mutations is high. In your body, there may be millions of bacteria that the antibiotic kills. But if just one of them has a mutation that makes it immune to the antibiotic, that one cell can reproduce quickly and then spread to other people. Most bacterial diseases have become immune to some or all of the antibiotics used against them through this process.
11. In your own words, describe what an antibiotic is. ______
______
12. Why do antibiotics lose their effectiveness after using them for a long time?______
______
Name 2 things that people should know about microbiology in everyday life.
13. ______
14. ______
15. Using inference from clues in this passage, what do you think the word “exploited”
means? ______
Plant Cells vs. Animal Cells Comprehension
Cells can be found in all living things. There are several types of cells. They are usually separated into prokaryotic or eukaryotic and are either plant or animal cells. An "animal" cell could be anything from a tiny, one-celled microorganism like an amoeba to a nerve cell from your brain. Plant cells are cells found in any plant that uses photosynthesis to make its own food.
The first classification of cells is whether they are prokaryotic or eukaryotic. Prokaryotic cells are simpler cells. They were probably the first cells on earth. Prokaryotic cells do not have a nucleus or any membrane-covered organelles. The only cells on earth that are prokaryotes are viruses and bacteria. Eukaryotic cells have a nucleus and membrane covered organelles. Things that have eukaryotic cells include animals, plants, protists, and fungi. Organelle means "little organ." Organelles are the parts inside a cell that have specific functions or jobs. Just as the human body has organs that do specific jobs, cells have organelles, or little organs, that do specific jobs in the cell. In the human body, the heart is an organ whose job is to pump blood. In a cell, the mitochondria are organelles whose job is to convert food into energy.
Plant cells and animal cells have many of the same characteristics, but they are different in some ways. Plant cells are easier to identify under a microscope because they have a rigid cell wall made of cellulose outside the cell membrane. This gives the plant, and the cell, structure and support. Animal cells do not have a cell wall.
Another way plant cells are different from animal cells is that plant cells usually have just one very large vacuole. Animal cells may have more than one vacuole, and they are smaller than a plant cell's. Vacuoles are used to store materials in the cell that may be used by the cell or wastes that must be moved out of the cell. Often, plant cells store water in the vacuole. When a plant doesn't get enough water, it must use the stored water in its vacuoles to live. This causes the plant to "wilt." When a plant wilts, it cannot support itself anymore. The water inside each cell's vacuole helps the plant to stand up, like air in a beach ball makes the ball "stand up." If the plant uses the stored water, then the plant becomes less firm and may finally become so limp that it lies on the ground. After watering, the limp plant will become firm and again "stand up."
Plants also have organelles called chloroplasts. Chloroplasts contain a green pigment called chlorophyll. This is what makes leaves appear green. This special organelle and the chemical chlorophyll enable plants to capture energy from the sun in a process called photosynthesis and convert the energy to sugars that the plant uses for food. Plants are the only living things on earth that can make their own food because of this special organelle. Animal cells do not have chloroplasts.
If plant and animal cells were in a survival contest, who do you think would win? One of the most important needs that must be met to survive is the need for food. Since plants can make their own food, they have a huge advantage over animals. All animals must hunt their own food, whether that food is a plant or another animal.
Instructions:
STEP 1 Read the previous page about plants vs. animal cells
Plant Cells Only
BOTH Animal Cells Only
STEP 2 List all the things that are common to both plant and animal cells in the center
STEP 3 List all of the characteristics that are found only in plant cells in the left side space
STEP 4 List all of the characteristics that are found only in animal cells in the right side space
STEP 5 Draw a plant cell and an animal cell below. Make sure to list the characteristics from your Venn diagram. What color would each type of cell be? What would the overall shape be? Would the cell have chloroplasts? Would the cell have a cell wall? Would the cell have a nucleus? How big would the vacuole be? What other organelles would be inside? (Use page C20 and C21 for resource information.) Make sure to color your cell.