Cellular levels of organization

Question 1

What are the principal parts of the cell?

Answer 1

The principal parts of a cell are the Cell membrane, cytoplasm, membranous organelles, non-membranous organelles and nucleus

Question 2

What are the principal parts of the cell membrane?

Answer 2

phospholipid bilayer, microvilli, cholesterol, membrane proteins (integral, transmembrane and peripheral proteins) and membrane carbohydrates

Question 3

The fluid mosaic model is the

Answer 3

Model that shows the membrane, which includes the phospholipid bilayer and proteins
Fluid: constituents move around such as lipids and some proteins
Mosaic: proteins dot the surface like a mosaic
COLD TEMP, make the membrane less fluid

Question 4

What are the principal parts of the cytoplasm?

Answer 4

Cytosol and organelles (membranous and non membranous)

Question 5

Name the structures of non-membranous organelles

Answer 5

Ribosomes, Centrosomes and cytoskeleton (microfilaments, intermediate filaments and microtubules)

Question 6

Name the structures of membranous organelles

Answer 6

Golgi apparatus, Endoplasmic reticulum (rough and smooth), mitochondria, lysosomes

Question 7

Parts that are contained within the Nucleus

Answer 7

Nuclear envelope, nucleolus and chromosomes/chromatids (dispersed or condensed)

Question 8

phospholipid bilayer?

Answer 8

Layer in the cellular membrane
Made up of
1) Phosphate head group (hydrophilic, polar=charge)
2) 2 FA tails (hydrophobic, nonpolar=nocharge)
This layer separates the ICF and ECF (intracellular fluid and extracellular fluid)

Question 9

cholesterol

Answer 9

Scattered throughout the membrane and adds stability to the cell membrane

Question 10

What is the function of membrane proteins

Answer 10

channels, enzymes, transporters, receptors, anchors and identity markers

Question 11

What are the types of membrane proteins

Answer 11

Integral, transmembrane, and peripheral

Question 12

What are integral and transmembrane proteins

Answer 12

Integral: integrated within the cell membrane, and have a hydrophobic and hyrophillic region
Transmembrane: extended across the entire membrane

Question 13

Peripheral Proteins

Answer 13

proteins that are attached to extracellular or intracellular region of integral proteins (periphery;outside of the cell membrane)

Question 14

What is the function of membrane proteins?

Answer 14

channels, enzymes, transporters, receptors, anchors, and identity markers

Question 15

Membrane Carbohydrates

Answer 15

Part of the cellular membrane on the outer surface (extracellular fluid)
- bound to proteins and lipids (glycoproteins and glycolipids)

Function:
Cell recognition (sperm recognizes an egg) and anchoring

Question 16

Name the functions of membrane carbohydrates

Answer 16

Cell recognition e.g how sperm recognizes egg cell
anchors cell together

Question 17

Microvilli

Answer 17

small projections of the cell membrane
Work to increase the surface area
best seen on cells of the small intestine and kidney

Question 18

What is the cytoplasm

Answer 18

area between inside of the cell membrane and outside of the nucleus

Question 19

Cytosol

Answer 19

intracellular gel-like fluid
contains water and suspensions of carbohydrates, lipids and proteins
may contain inclusions ex) melanin (pigment) , glycogen (stored glucose)

Question 20

organelles

Answer 20

organelles are surrounded by the cytosol
Organelles are structures that perform a specific function which is essential for life
non-membranous and membranous

Question 21

Non-membranous organelles are

Answer 21

are in direct contact with the cytosol

Ribosomes, Centrosomes and Cytoskeleton (microfilaments, intermediate filaments and microtubules)

Question 22

Membranous organelles

Answer 22

surrounded by a membrane that isolates them from the cytosol
(need a different environment inside them to function)

Mitochondria, Endoplasmic reticulum, Lysosomes, Golgi apparatus

Question 23

Centrosome

Answer 23

dense area of the cytoplasm, usually contains 2 centrioles

organizes microtubules of cytoskeleton and spindle apparatus for cell division

Question 24

Cytoskeleton function and what they’re made of

Answer 24

All types support cell shape and are formed from proteins
- important for cell movement, cell division, movement/anchoring of organelles and proteins (e.g receptors, enzymes)

Types: Microfilaments, intermediate filaments, and microtubules

Question 25

Microfilaments

Answer 25

a part of the cytoskeleton
made of actin
Function:
muscle contraction (w/ myosin)
maintenance of cell shape and projections (e.g microvilli)
involved in cytokinesis (cell division)

Question 26

Intermediate filaments

Answer 26

part of the cytoskeleton
composition is tissue-specific e.g keratin
Function:
supports the cytoplasm (scaffolding for the cell)

Question 27

Microtubules

Answer 27

hollow tubes made of tubulin
Function:
forms centrioles, spindle apparatus, cilia (short, whip-like) and flagella (long, wave-like)
Structural, move or secure organelles in place (keep surface tidy)

Question 28

Mitochondria

Answer 28

site of ATP synthesis
use to be independent and can no longer live independently, depending on the nucleus of the cell (code for diff genes; separate)
have a double membrane
contain their own DNA, RNA, and proteins

Question 29

endoplasmic reticulum

Two types and What do they synthesize

Answer 29

membranous network throughout cytoplasm
2 types:
Rough ER
ribosomes attached
synthesis of secretory, lysosomal, and membrane proteins
Smooth ER
lacks attached ribosome
continuous with RER
synthesizes lipids and steroid hormones

Question 30

The difference in function between the rough endoplasmic reticulum and smooth endoplasmic reticulum

Answer 30

RER (attached ribosomes)
synthesizes secretory, lysosomal, and membrane proteins

SER (lacks attached ribosomes)
synthesizes lipids and steroid hormones

Question 31

Golgi apparatus

Answer 31

membranous organelle has stacks of membrane discs (1/cell) tightly packed together, “c-shaped”
Modifies (trims or adds CHO groups), sorts, packages and delivers proteins/lipids to the cell membrane, lysosomes, or for secretion (cellular post office)

Question 32

Lysosomes

Answer 32

membranous organelle filled w/ digestive enzymes
digest bacteria, viruses, worn-out organelles (clean up function)
kept away from cyotsol as it can digest anything

Question 33

Nucleus

Answer 33

largest membranous organelles
cell control centre
cell may have 1 or more nuclei

Parts:
1) nuclear envelope
2) nucleolus
3) chromosomes/chromatids

Question 34

nuclear envelope

Answer 34

double membrane with nuclear pores, connected to the ER

Question 35

nucleolus

Answer 35

non-membranous
a part of the nucleus
dense (less light gets through - tips of nucleolus) region of DNA +RNA + proteins where ribosomes are made and assembled

Question 36

Difference between chromosomes/chromatids

Answer 36

made of DNA and histone proteins
A part of the Nucleus

Dispersed (chromatin)
- DNA uncoiled, chromosomes not individually visible
- in this form most of the time when the cell isn’t dividing

Condensed + chromosomes
- form is easy to manipulate around cell
- individually visible
- found in dividing cells (during mitosis/meiosis)

Question 37

Functions of Microfilaments

Answer 37

Involved in cytokinesis
Maintenance of cell shape
Muscle contraction w/ myosin

Question 38

Function of Microtubules

Answer 38

Structural, helps move or secure organelles in place

Question 39

Function of intermediate filaments

Answer 39

Support cytoplasm (Scaffolding of cell)