Question 1

What are cells?

Accepted Answer

The building block of living organisms

Question 2

What is the smallest unit of living material that can still be considered alive?

Accepted Answer

A single cell

Question 3

What is the surface-area-to-volume ratio?

Accepted Answer

The amount of surface area an object has, compared to the amount of volume it has

(limits the maximum size of cells; bigger objects have a lower surface-area-to-volume area)

Question 4

Why can't giant cells exist?

Accepted Answer

If the cell gets too big, its membrane is too small for nutrients to pass through and feed the increased cellular volume

(because of the surface-area-to-volume ratio)

Question 5

What are the two types of cells?

Accepted Answer

Prokaryotes and eukaryotes

Question 6

What is an optical/light microscope?

Accepted Answer

A device that focuses light on an object, magnifying it

Question 7

What are electron microscopes?

Accepted Answer

A microscope that uses a beam of electrons to illuminate an object

(used to parts of a cell where light can't reach)

Question 8

What is cytoplasm?

Accepted Answer

The thick solution that fills cells

Question 9

What is the nucleoid?

Accepted Answer

The area of a prokaryotic cell that contains its genetic material

(unlike the nucleus of a eukaryotic cell, it has no nuclear membrane)

Question 10

What is the cell wall?

Accepted Answer

A rigid outside-layer of some cells that help them maintain shape

(most common in plant cells: animal cells usually don't have cell walls)

Question 11

What is the plasma membrane/cell membrane?

Accepted Answer

The membrane in all cells that separates the cell from its outside environment

Question 12

What are flagella?

Accepted Answer

Long threadlike structures that allow some cells to "swim"

Question 13

What is the capsule in prokaryotic cells?

Accepted Answer

A sticky outer layer that can protect the cell and prevent it from drying out

Question 14

What is endosymbiotic theory/symbiogenesis?

Accepted Answer

The leading evolutionary theory of how eukaryotic cells came from prokaryotic cells

(says that mitochondria and chloroplasts were once separate from prokaryotes, but came to live inside cells)

Question 15

What is the difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells are more complex and have organelles

(animal/plant/fungi cells are eukaryotes, bacteria are prokaryotes)

Question 16

What are organelles?

Accepted Answer

A specialized part of a cell

(like an organ in your body, but for a cell)

Question 17

What is the phospholipid bilayer?

Accepted Answer

A layer around cells of polar lipids that selectively allow molecules in and out of the cell

Question 18

What are peripheral proteins?

Accepted Answer

Proteins on the surface of the cell membrane

(often used for transportation and communication)

Question 19

What are integral proteins?

Accepted Answer

Proteins that pass all the way through the cell membrane

(often are used for transportation of larger molecules)

Question 20

What are transmembrane proteins?

Accepted Answer

Proteins that extend all the way through the cell membrane

Question 21

What is the fluid-mosaic model?

Accepted Answer

A model for describing cell membranes, containing the phospholipid bilayer and the various proteins that travel through it

Question 22

What are lipid-bound proteins?

Accepted Answer

Proteins stuck inside the cell membrane

(very rare)

Question 23

What are channel proteins?

Accepted Answer

Proteins that allows things to pass through the cell membrane

(goes with the concentration gradient and doesn't require ATP)

Question 24

What are carrier proteins?

Accepted Answer

Proteins that use energy to carry a protein from one side of the membrane to the other

Question 25

What are adhesion proteins?

Accepted Answer

Proteins that form junctions between cells, sticking the cells together

Question 26

What are receptor proteins?

Accepted Answer

Proteins embedded in the cell membrane that can receive chemical signals

Question 27

What are desmosomes?

Accepted Answer

Specialized adhesion proteins that are responsible for holding tissues together

Question 28

What are carbohydrate side chains?

Accepted Answer

Carbohydrate chains on the cell membrane

Question 29

What is the nucleus?

Accepted Answer

Largest cell organelle that controls the cells functions and houses its DNA

Question 30

What is the nucleolus?

Accepted Answer

A region in the cell nucleus that produces the cells ribosomes

Question 31

What are ribosomes?

Accepted Answer

Cell organelles that synthesize proteins for the cell

Question 32

What is the endoplasmic reticulum (ER)?

Accepted Answer

A continuous channel organelle that contains a rough and smooth section

Question 33

What is the rough endoplasmic reticulum?

Accepted Answer

Part of the ER that contains ribosomes and is attached to the nucleus

Question 34

What is the smooth endoplasmic reticulum?

Accepted Answer

Part of the ER that lacks ribosomes and makes lipids

Question 35

What is the Golgi apparatus/Golgi body?

Accepted Answer

A cell organelle that "processes and packages" proteins after they are produced

Question 36

What are vesicles in the Golgi apparatus?

Accepted Answer

Sealed droplets that contain proteins

(produced by the Golgi apparatus)

Question 37

What are mitochondria?

Accepted Answer

The powerhouses of the cell that convert organic molecules into ATP

Question 38

What cells have the most mitochondria?

Accepted Answer

Cells that require a lot of energy, such as muscle cells

Question 39

What is adenosine triphosphate (ATP)?

Accepted Answer

The most common energy molecule in cells

Question 40

What are cristae in mitochondria?

Accepted Answer

Folds in the inner parts of the mitochondria

Question 41

What are lysosomes?

Accepted Answer

Small, membrane-enclosed organelles that break down old organelles and debris

Contain hydrolytic enzymes that digest macromolecules

Question 42

What are centrioles?

Accepted Answer

Cylindrical organelles that help during cell division

(they create spindle fibers during cell division)

Question 43

What are vacuoles?

Accepted Answer

Fluid-filled organelles in cells that store water, food, and wastes

(small in animal cells, big in plant cells)

Question 44

What are peroxisomes?

Accepted Answer

Organelles that break down various substances and produce hydrogen peroxide as a byproduct

Question 45

What is the cytoskeleton?

Accepted Answer

A network of proteins in cells that help the cell keep its shape

Question 46

What are microfilaments?

Accepted Answer

Part of the cytoskeleton that assist with cell movement

Question 47

What are cilia?

Accepted Answer

Thin hairs around some cells that allow them to move

(cilium is Latin for eyelash)

Question 48

What are chloroplasts?

Accepted Answer

An organelle in plant cells that are involved with photosynthesis

Question 49

What is the central vacuole?

Accepted Answer

A large vacuole inside plant cells that stores water

Question 50

What happens when a plant's cell's central vacuoles are empty?

Accepted Answer

The plant begins to wilt

Question 51

What is diffusion?

Accepted Answer

The passive spreading out of molecules in a space

Question 52

What is osmosis?

Accepted Answer

A special case of diffusion where water moves through a semipermeable membrane

Question 53

What is facilitated diffusion/transport?

Accepted Answer

Passive movement of molecules across the cell membrane with the aid of membrane transport proteins

(some molecules (e.g., carbon dioxide, oxygen) can diffuse across the cell membrane directly, but others need facilitated diffusion to help them)

Question 54

What are membrane transport proteins?

Accepted Answer

Proteins that help molecules pass through the cell membrane, such as carrier and channel proteins

Question 55

What are aquaporins?

Accepted Answer

Water channels that facilitate the transport of water across the cell membrane

(type of channel optimized for water)

Question 56

What is a concentration gradient?

Accepted Answer

The difference in concentration between two areas of a substance

Question 57

What is simple diffusion?

Accepted Answer

Movement of molecules across a cell membrane without help from carrier proteins

Question 58

What is the difference between simple diffusion and facilitated diffusion?

Accepted Answer

Simple diffusion: Movement of molecules without the use of carrier proteins (passively float through channel proteins)

Facilitated diffusion: Movement of molecules with the help of carrier proteins

Question 59

What is passive diffusion/transport?

Accepted Answer

Difussion that occurs without any outside energy

(simply occurs due to the concentration gradient)

Question 60

What is tonicity?

Accepted Answer

The concentration of a substance compared to another substance

(hypertonic, hypotonic, isotonic)

Question 61

What does it mean for an environment to be isotonic to a cell?

Accepted Answer

The solution concentration is the same inside and outside the cell

Question 62

What does it mean for the environment to be hypertonic to a cell?

Accepted Answer

The environment has a higher concentration (of something) than the cell

(causes net out-flow of water)

Question 63

What does it mean for the environment to be hypotonic to a cell?

Accepted Answer

The environment has a lower concentration (of something) than the cell

(causes net in-flow of water)

Question 64

What is the difference between hypertonic and hypotonic?

Accepted Answer

If the environment is hypertonic compared to a cell it has a higher concentration, while if it is hypotonic it has a lower concentration

Unit 2: Cell Structure and Function, AP Biology Flashcards