Cell Work Sheet

Dr. Mary Cat Flath

Instructions: Using the attached composite cell diagram with numbered parts, name the numbered cell structure and then fill in the corresponding blanks.

1. Name the cell part: cell membrane

This outer boundary of the cell is composed of a bilayer of (A) phospholipids molecules and (B) protein.

The molecules named in (A) above, are positioned so that the phosphate portion of the molecules are at the surface of the membrane and make these surfaces water-soluble, while the fatty acid portion of the molecules compose the interior of the membrane and make the membrane fat-soluble. The unique structure of these molecules make this membrane “selectively permeable” which means it allows some things to pass through, while it excludes others. In general, small, fat-soluble substances pass through this membrane more easily than water-soluble substances.

2. Name the cell part. cytoplasm

This jelly-like fluid is composed of 70% water.

It fills the spaces between the cell membrane and the nuclear membrane, and suspends the cellular organelles, so they can each perform their specific function.

3. Name the cell part. Golgi apparatus

This “stack of pancakes” functions to modify, package & transport newly made proteins in the cell. Each “pancake” is called a cisternae.

4. Name the cell part. nucleus

This central core of the cell functions to control all cellular activities. It contains DNA, which directs protein synthesis in the cell. The most important function of the proteins made by the cell is that some serve as biological catalysts called enzymes.

5. Name the cell part. Nuclear envelope

This membrane surrounding #4 above, is similar to the cell membrane, however it fuses at some points to form nuclear pores. Name two things that readily pass through these pores. mRNA & ribosomes

6. Name the cell part. nucleolus

This dense, spherical organelle within the nucleus of the cell is composed of RNA & protein. It functions in the synthesis of ribosomes.

7. During the majority of a cell’s life, the DNA is loosely coiled with protein, and is referred to as chromatin.

How would the DNA appear in a cell preparing to divide? As chromosomes

8. Name the cell part. Centrioles

This pair of cylinders composed of microtubules is always located near the nucleus of the cell, and at right angles to one another. They aid in the movement of chromosomes during cell division.

9. Name the cell part. mitochondrion

The inner membrane of this kidney-shaped organelle is folded into shelf-like partitions called cristae. The function of this organ is to release energy from the nutrients we eat in a process called cellular respiration. Accordingly, this organelle is commonly called the “power house”.

10. Name the cell part. Lysosomes

These membranous sacs contain digestive enzymes that destroy worn cell parts and foreign debris. Because they function in this manner, they are commonly called the “suicide sacs” of the cell. By what transport process does the cell bring a foreign particle in to destroy it? endocytosis

11. Name the cell part. Cytoskeleton

These protein filaments provide a framework for the cell, and are sometimes called the “muscle & bones” of the cell. They include three types of protein filaments. Name them microtubules, microfilaments &

intermediate filaments.

12. Name the cell part. ribosomes

These organelles are composed of RNA and protein, and may dispersed throughout the cytoplasm or studded on membranes of the rough endoplasmic reticulum. In either location, they function as the site for protein synthesis. Besides enzymes, name some other functions of proteins. Hormones, antibodies, structure, transport

13. Name the cell part. Smooth ER

This maze of membranous channels functions to synthesize

lipids & cholesterol. What function(s) does the macromolecule made at this organelle serve? Energy store/membrane component

14. Name the cell part. Rough ER

This maze of membranous channels is studded with ribosomes. Accordingly, this organelle functions to produce proteins.

Any macromolecule made at this organelle must travel to the

Golgi to be modified, packaged, and transported within or out of the cell.

15. Name the cell part. cilia

These eyelash-like cell membrane extensions function to push substances through passageways. Name two human cells/tissues that possess these extensions. respiratory tract and fallopian tube.

16. Name the cell membrane extensions. Microvilli These extensions serve to increase the surface area of the cell membrane. These extensions are found in lining of the small intestine.

17. Name the long, tail-like extension. flagellum

The function of this extension is locomotion. Name the only human cell type that possesses #17. sperm