microscope, cell parts, and cell theory

Question 1

cell theory

Answer 1

1. all living things are made up of cells
2. cells are the basic unit of structure and organization in organisms
3. all cells come from existing cells

Question 2

nucleus

Answer 2

• the control center
• contains dna
• codes instructions for making proteins and other important molecules

Question 3

cytoplasm

Answer 3

the portion of the cell outside of the nucleus

Question 4

cytoskeleton

Answer 4

a network of protein filaments

• can also help transport materials
• helps the cell maintain its shape and is also involved in movement

Question 5

microfilaments

Answer 5

threadlike structures made up of a protein called actin

• help cells move

Question 6

ribosomes

Answer 6

small particles of rna and protein found throughout the cytoplasm

Question 7

microtubules

Answer 7

hollow structures made up of proteins known as tubulins

• plays a critical role in maintaining cell structure
• helps build projections from the cell surface
  
  • cilia
  • flagella

Question 8

endoplasmic reticulum (er)

Answer 8

internal membrane system

• where lipids, proteins, and other materials that are exported from the cell are synthesized

Question 9

rough er

Answer 9

has ribosomes found on its surface

• newly made proteins leave ribosomes and enter rough er
• proteins made in rough er are those that will be released or secreted from the cell

Question 10

centrioles

Answer 10

an organelle also formed by tubulins

• located near the nucleus
• helps organize cell division
• not found in plant cells

Question 11

smooth er

Answer 11

ribosomes not found on the surface

• in many cells contains collections of enzymes that perform specialized tasks
  
  • synthesized lipids and detoxification of drugs
• plays an important role in the synthesis of carbohydrates

Question 12

chloroplasts

Answer 12

the biological equivalent of solar power plants

• capture the energy from sunlight and convert it into chemical energy stored in food during photosynthesis
• inside containsgreen pigment chlorophyll

Question 13

golgi apparatus

Answer 13

an organelle where proteins move after being produced in the rough er

• modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release from the cell
• proteins are transported to their final destination when they leave the golgi apparatus

Question 14

vacuoles

Answer 14

large saclike, membrane-enclosed structures

• stores materials like water, salts, proteins, and carbohydrates
• many plant cells have a single large central vacuole

Question 15

lysosomes

Answer 15

small organelles filled with digestive enzymes

• breaks down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cells
• can also break down organelles that are no longer helpful to the cell

Question 16

mitochondria

Answer 16

power plants of the cell

• nearly all eukaryotic cells, including plants, have mitochondria
• convertthe chemical energy stored in food molecules into compounds that are more convenient for the cell to use

Question 17

cell membrane

Answer 17

cell membrane: a barrier that surrounds all cells

• generally made up of a lipid bilayer
• regulates what enters and leaves the cell
• protects and supports the cell

Question 18

lipid bilayer (phospholipid)

Answer 18

a double-layered sheet

• gives cell membranes a flexible structure

Question 19

cell wall

Answer 19

a strong supporting layer around the cell membrane

• support, shape, and protect the cell
• many plants and fungi have cell walls
• most animal cells do not have a cell wall

Question 20

prokaryote

Answer 20

• does not have a nucleus
• dna is found in the cytoplasm, does not have an enclosure or membrane
• smaller
• simpler
• single-celled organisms

Question 21

eukaryote

Answer 21

• does have a nucleus
• dna is fully enclosed in a nuclear membrane
• larger
• more complex
• some are single-celled, many are multicellular

Question 22

both prokaryotes and eukaryotes

Answer 22

• contains dna
• living cell