Lesson 3: Cell Structures and Functions

Question 1

is reflected in the different shape and sizes of cells

Answer 1

cellular diversity

Question 2

what happens when the cell grows bigger?

Answer 2

its surface area becomes too small to maintain its life functions

Question 3

two types of cells that differ in internal organizations:

Answer 3

1. prokaryotic cells
2. eukaryotic cells

Question 4

lack a nuclear envelope and membrane-bound organelles

Answer 4

prokaryotic cells

e.g. bacterial cells

Question 5

• are generally larger and have very distinct nuclei that are clearly surrounded by nuclear membranes
• they also have numerous membrane-bound organelles found in the cytoplasm

Answer 5

eukaryotic cells

e.g. protists, plants, fungi, animals

Question 6

why is cell division in eukaryotic cells comparatively different from that of prokaryotic cells?

Answer 6

because of the intricate organization of the DNA in eukaryotic cells

Question 7

is the most common type of cell division in eukaryotes

Answer 7

mitosis

Question 8

type of cell division found in prokaryotes

Answer 8

binary fission

simpler compared to mitosis

Question 9

why are secretory cells located in glands expected to have more ribosomes, Golgi bodies, and ER?

Answer 9

Because they work hard in secreting the materials that the cells need

Question 10

prokaryotic cells

a sticky outer layer that provides protection

Answer 10

capsule

Question 11

prokaryotic cells

a structure that confers rigidity and shape to the cell

Answer 11

cell wall

Question 12

prokaryotic cells

a structure that serves as permeability barrier

Answer 12

plasma membrane

Question 13

prokaryotic cells

a genetic material

Answer 13

plasmid

Question 14

prokaryotic cells

a DNA-containing region within the cytoplasm

Answer 14

nucleoid

Question 15

prokaryotic cells

region where chromosomes (DNA), ribosomes and various inclusions are found

Answer 15

cytoplasm

Question 16

prokaryotic cells

the site where protein is synthesized

Answer 16

ribosome

Question 17

prokaryotic cells

a hair-like appendage that functions in adhesion

Answer 17

pilus (plural,pili)

Question 18

prokaryotic cells

facilitates movement of bacteria

Answer 18

flagellum

Question 19

eukaryotic cells have three main parts:

Answer 19

1. cell membrane
2. cytoplasm
3. nucleus

Question 20

sometimes called the plasma membrane, it is the outemost covering of animal cells

Answer 20

cell membrane

Question 21

describes the cell membrane as a phospholipid bilayer sandwiched by a coat of protein on either surface

Answer 21

Davson-Danielli model

Question 22

• now the widely accepted model
• decribes the plasma membrane as a mosaic of of protein that are embedded or attached to a fluid bilayer of lipid

Answer 22

Singer-Nicolson model or fluid mosaic model

Question 23

• it regulates the substances that enter and exit the cell
• serves as a solvent for integral membrane proteins that run across the lipid bilayer

Answer 23

cell membrane

Question 24

• all the materials in the cell that surround the nucleus
• ground substance and the biggest part of the cell where organelles are found

Answer 24

cytoplasm

Question 25

is a network of intercommunicating channels in the cytoplasm

Answer 25

endoplasmic reticulum (ER)

Question 26

two types of ER:

Answer 26

- rough endoplasmic reticulum (RER) - smooth endoplasmic reticulum (SER)

Question 27

- plays a role in the **production of protein** - there are ribosomes attached on its surface

Answer 27

rough ER

Question 28

- plays a role in **manufacture and metabolism of lipids** - is more tubular and non-granular structure due to absence of ribosomes

Answer 28

smooth ER ## Footnote has a role in the biosynthesis of steroid hormones

Question 29

- is composed of sets of cisternae and numerous vesicles - processing, packaging and sorting of secretory materials

Answer 29

Golgi apparatus

Question 30

# fill in the blank after protein is synthesized by the 1. ____, it passes into the channel of the 2. ________ and moves into the fluid-filled sacs of the 3._______

Answer 30

1. ribosomes 2. ER 3. Golgi apparatus

Question 31

contains enzymes that help in the **chemical oxidation of food molecules** and **produces energy** in the form of ATP

Answer 31

mitochondrion | plural, *mitochondria*

Question 32

prominent parts of the mitochondrion

Answer 32

crista (plural, cristae) and matrix

Question 33

are numerous folds of the inner membrane of the mitochondrion

Answer 33

cristae

Question 34

is the space inside the inner membrane of the mitochondrion

Answer 34

matrix

Question 35

why do liver cells have more mitochondria compared to skin cells?

Answer 35

because liver cells are active most of the time compared to skin cells which are less active

Question 36

contain a number of **enzymes** for intracellular digestion

Answer 36

lysosomes ## Footnote - contains around 40 kinds of enzymes that help digest food, disease-causing bacteria engulfed by wbc, and worn-out and broken parts of the cell

Question 37

- large, dense granules with membranes - these fuse with the cell membrane to secrete substances

Answer 37

secretory granules

Question 38

store fatty acids and sterols

Answer 38

lipid droplets

Question 39

what happens when lipid droplets are stained with osmium tetroxide?

Answer 39

they appear as black spherical bodies

Question 40

are non-membraneous substances and structures suspended in the cytoplasm with varying funtions

Answer 40

cytoplasmic inclusions

Question 41

- site where proteins are made - most numerous of all cytoplasmic structures

Answer 41

ribosomes

Question 42

proteins that will be exported outside of the cell are produce by?

Answer 42

bound ribosomes | ribosomes attached to the ER

Question 43

proteins that are needed by the cell itself are produced by?

Answer 43

free ribosomes | float freely in the cytoplasm

Question 44

what central role in cell division does the centriole play?

Answer 44

where it participates in the **formation of the mitotic spindle**

Question 45

composed of nine groups of parallel subunits arranged in a longitudinal fashion

Answer 45

centriole

Question 46

is a structure that helps cells maintain their shape and internal organization ## Footnote note: not in the book

Answer 46

cytoskeleton

Question 47

together they form the cytoskeleton:

Answer 47

microtubules and microfilaments

Question 48

- composed of linear polymers of tubulin - forms the spindle apparatus that appears in cell division

Answer 48

microtubules

Question 49

support the cell to maintain its structure and shape as it provides resliency against forces that can altar the shape

Answer 49

microfilaments

Question 50

are examples of microfilaments that aid in the movement of chromosomes during cell division

Answer 50

spindle fibers

Question 51

abundant in liver cells, play an important role in the glucose cycle

Answer 51

glycogen granules

Question 52

do not require staining by dyes because they already posses their own color

Answer 52

pigments

Question 53

- site where **nucleic acids** are synthesized - **directs** all the activities of the cell - storage of **heriditary** factors

Answer 53

nucleus

Question 54

the nucleus is the source of the molecule responsible for various cellular functions such as **genetic coding and expression**

Answer 54

ribonucleic acid (RNA)

Question 55

two layered outer limit of the nucleus separating it from the cytoplasm

Answer 55

nuclear membrane

Question 56

dense protein rich substance inside the the nucleus

Answer 56

nucleoplasm

Question 57

- it is suspended in the nucleoplasm - resposible for ribosome formation

Answer 57

nucleolus

Question 58

# familiarize only: what is being transcribed and assembled in the nucleoulus?

Answer 58

rRNA

Question 59

act as **selective channels between the cytoplasm and the inside of the nucleus**, selectively allowing molecules which contain the correct localization signal to pass in and out

Answer 59

nuclear pores | can be seen in the nuclear envelope

Question 60

made up of DNA and proteins and forms chromosomes during cell division

Answer 60

chromatin | found inside the nucleus

Question 61

contain the genes inherited by the offspring from their parents

Answer 61

chromosomes

Question 62

structures that are found in plant cells only:

Answer 62

1. cell wall 2. water vacuoles 3. plastids

Question 63

outermost rigid covering of plant cells

Answer 63

cell wall ## Footnote provide strength and rigidity to the cell

Question 64

the cell wall is primarily composed of?

Answer 64

cellulose

Question 65

two types of cell walls

Answer 65

primary and secondary wall | with a lamella sandwiched in between - *middle lamella*

Question 66

is the first to form, particularly during the growth period of the cell | a type of cell wall

Answer 66

primary wall

Question 67

when formed, expansion in cell size can no longer be expected

Answer 67

secondary wall

Question 68

- are larger and more centrally located in plant cells - store enzymes and waste products

Answer 68

water vacuoles

Question 69

# familiarize only: in mature plant cells, it could occupy 90% of the volume

Answer 69

water vacuoles

Question 70

# familiarize only: in what form can waste materials inside the vacuoles be in?

Answer 70

in the form of posionous substances that needs to be isolated | e.g. cyanide

Question 71

carry out photosynthetic function in plants

Answer 71

plastids

Question 72

example of plastids:

Answer 72

1. chloroplasts 2. chromoplasts 3. leucoplasts

Question 73

contain chlorophyll which is designed to absorb sunlight in the initial step of photosynthesis

Answer 73

chloroplasts

Question 74

synthesize and store pigments such as yellow, carotene, xanthophylls, and various red pigments

Answer 74

chromoplasts

Question 75

- colorless - store food such as starches, lipids and proteins - found in storage organs

Answer 75

leucoplasts