Organelles of the Cell

Question 1

What are the 3 general parts of the cell?

Answer 1

Nucleus, Plasma membrane, and cytoplasm (organelles)

Question 2

Structure of the Nucleus

Answer 2

• Contains chromosomes and surrounded by a membrane
• The membrane has openings called nuclear pores that allow materials to enter and leave
• found in eukaryotes
  -Contains the nucleolus

Question 3

The nucleolus

Answer 3

Helps form ribosomes
RNA is manufactured here

Question 4

Chromosomes

Answer 4

-Human somatic (body cells) cells = 46 (diploid
- human sex cells = 23 (haploid)
- rod shapes, carries genes (pieces of DNA that carry a certain trait)

Question 5

Function of Nucleus

Answer 5

To transmit genetic info from one generation to the next. Controls all cell functions

Question 6

Structure of Plasma Membrane

Answer 6

• called the fluid (movement) mosaic (pattern) model
• Made of a phospholipid bilayer, it has a phosphate group as well as two fatty acid chains
• The phospholipid molecules have a hydrophobic, water-repelling, and hydrophilic, water-attracting side.
• The hydrophilic ends are located towards the outside and inside of the membrane.
• The hydrophilic ends are embedded within the membrane away from contact with water (cytoplasm, intestinal fluid).
• two types of proteins in membrane, surface and integral

Question 7

Function of Plasma membrane

Answer 7

Controls what enters/leaves the cell. Selectively permeable / semi-permeable

Question 8

Integral Proteins

Answer 8

• Penetrate the whole membrane
• act as channel proteins, move materials in/out of the cell

Question 9

Surface Proteins

Answer 9

• Move along the surface; may have carbohydrate chains extending on the outside

Question 10

Major Histocompatibility Complex

Answer 10

• distinguishes self from nonself (outside of the cell).
  Important in transplants (blood transfusion)

Question 11

Cholesterol

Answer 11

• steroid = helps keep fluid, mosaic membrane fluid
• if too hot it holds the structure in place, if too cold it prevents solidification

Question 12

Cytoplasm

Answer 12

The gel-like material that fills the cells, also called cytosol. Organelle are located here

Question 13

Structure of Mitochondria

Answer 13

-kidney bean-shaped, numerous
- double membrane; the inner membrane is curved = cristae
-the curvature increases surface area
- Have own DNA and ribosomes

Question 14

What is Endosymbiont Theory?

Answer 14

The idea that mitochondria existed once independent from the cell

Question 15

Function of Mitochondria

Answer 15

• aerobic respiration takes place on the curved inner membrane
• production of ATP, energy molecules using oxygen

Question 16

What is aerobic respiration?

Answer 16

The use of oxygen to produce adenosine triphosphate, energy molecules.

Question 17

Structure of Ribosomes

Answer 17

• have no membrane surrounding them

Question 18

Function of Ribosomes

Answer 18

• synthesize proteins, instructions are transmitted from DNA/RNA
• function as enzymes = biological catalysts
• build structures, act as antibodies

Question 19

Where are ribosomes found the most?

Answer 19

Stomach, pancreas, salivary glands

Question 20

Structure of Endoplasmic reticulum

Answer 20

Two types
- smooth ER = has no ribosomes
- Rough ER = has ribosomes, has a double membrane with a channel to allow materials to pass

Question 21

Function of Endoplasmic reticulum

Answer 21

• Smooth = neutralizes toxins and drugs, helps form lipids
• Rough = transports proteins made by ribosomes out of cells,
  -free ribosomes = make proteins used in the cell

Question 22

Which part of the body has the most mitochondria?

Answer 22

Muscles

Question 23

Which part of the body has the most smooth ER?

Answer 23

Liver

Question 24

Which part of the body has the most rough ER?

Question 25

Structure of Golgi Apparatus

Answer 25

- named after the man who discovered them - sac like structures, flattened - usually found near endoplasmic reticulum

Question 26

Where are most of the Golgi Apparatus' found?

Answer 26

Where ever there is secretion, like glands, hormones, tear ducts, mucus.

Question 27

Function of Golgi Apparatus

Answer 27

- To package materials (proteins = enzymes) prior to shipment out of the cell. - these packaged materials form secretory vesicles which travel to the plasma membrane to merge and be released

Question 28

Structure of Lysosomes

Answer 28

- stomach of the cell - round vesicles = contains a highly destructive enzyme that can destroy the cell if it got out

Question 29

Function of Lysosomes

Answer 29

- To digest food, - to destroy foreign invaders like bacteria, - to destroy old and damaged cells = autolysis

Question 30

What are free radicals?

Answer 30

Highly reactive product of some metabolic reactions. These radicals can react with molecules in the cell that cause problems

Question 31

Structure of Peroxisomes

Answer 31

-rounded structure - contain hydrogen peroxide

Question 32

Function of peroxisomes

Answer 32

- detoxify - To rid the cell of all free radicals - convert free radicals to hydrogen peroxide (H2O2) - H2O2 is broken down by catalase

Question 33

What is Catalase?

Answer 33

It's also called Hydrogen Peroxide. This is the enzyme that breaks down H2O2 into water and oxygen H2O2 ----> 2 H2O + O2

Question 34

Function of Cytoskeleton

Answer 34

The framework of the cell and helps hold the cell together

Question 35

Structure of Cysoskeleton

Answer 35

Made up of Microfilaments, Microtubules, Intermediate filaments

Question 36

Structure of Microfilaments

Answer 36

Thin fibers made of Myosin, protein that makes up muscles

Question 37

Function of Microfilaments

Answer 37

Motility of cytoplasm to move substances in the cell = cytoplasmic stream

Question 38

Structure of Microtubules

Answer 38

tube shaped = strength

Question 39

Function of Microtubules

Answer 39

- give structure and strength to the cell - hold organelles on place

Question 40

Structures of Intermediate filaments

Answer 40

short, fibers

Question 41

Function of Intermediate filaments

Answer 41

help maintain organelles in place

Question 42

Function of messenger RNA

Answer 42

carry messages that contain instructions for protein synthesis from DNA gene in the nucleus to the ribosomes in the cytoplasm