Aashka Chokshi : CHAPTER 2 - Cytology

What does cytology mean?

The study of cells

What is the cell theory?

A theory which states that all living organisms are composed of cells, cells are the basic unit of life, and new cells come from existing cells.

Who are the three scientists that came up with the cell theory?

Matthias Schleiden, Theodor Schwann and Rudolf Virchow.

How are cells limited in size?

By the surface area-to-volume ratio, which affects the efficiency of nutrient and waste exchange.

What does pro- mean?

Before

What does karyo- mean?

Nucleus

What are fimbriae?

Hair-like appendages on the surface of prokaryotic cells, used for attachment

What is the nucleoid?

Region within a prokaryotic cell where the genetic material (DNA) is localized.

What does "-oid" mean?

Resembles

What does "eu-" mean?

True

How big are animal cells compared to prokaryotic cells?

100 times larger

What is the cell membrane?

The semipermeable membrane surrounding the cytoplasm of a cell, regulating the passage of substances in and out of the cell.

What does the cell membrane act as?

A barrier that controls which substances can enter or leave the cell

What does semi-permeable mean?

Allowing certain substances to pass through while preventing others

Describe the phospholipid bi-layer?

A double layer of phospholipids that forms the cell membrane, with hydrophilic (water-loving) heads facing outwards and hydrophobic (water-fearing) tails facing inwards.

What does "philia" mean?

Love or Like

What does "phobic" mean?

Afraid

What are microvilli?

Projections on the surface of some cells that increase surface area for absorption.

What is the cytoplasm made up of?

The jelly-like substance that fills a cell and holds the organelles in place

What happens when too much waste product accumulates in the cell?

It can lead to a toxic cell

What do all living things need to be surrounded by?

A cell membrane to maintain homeostasis

What is the purpose of the phospholipid bi-layer?

Separates the two fluid compartments

What are embedded proteins?

Proteins that are partially or entirely inserted into the phospholipid bilayer of the cell membrane

What are ion channels?

Allow ions to pass in or out of the cell, can open or close.

What are transporter (carrier proteins)?

Proteins which bind to certain molecules and transport them across the cell membrane (Active transport, requires ATP)

What are enzymes?

Catalysts or proteins that speed up chemical reactions

What are receptor sites?

Receptors which recognize molecules and initiate a certain response

What are recognition sites?

Allows white blood cells to recognize your cells from foreign cells

What are side effects?

When certain receptor sites are activated that cause unwanted changes in cellular activity.

What are two immunosuppressant drugs?

Corticosteroids and Prednisone

What is a thalidomide?

A drug to help combat morning sickness for expecting mothers

What was the side effect of thalidomide?

Babies being born with extreme birth defects like missing arms and legs

What is the nucleus?

A membrane-bound organelle that contains the cell's genetic material (DNA)

What is the nucleolus?

Where RNA is stored

What are chromatin?

Uncoiled DNA

What are chromosomes?

Coiled DNA in the shape of an ‘X’

What is the Endoplasmic Reticulum (ER)?

A network of tubes which transport chemicals within the cell

What is the function of the ER?

Transports chemicals within the cell

What is the function of the Smooth ER?

It is involved in lipid synthesis

What is on the rough ER?

Protein Synthesis

What are ribosomes?

Organelles responsible for protein synthesis

What is the Golgi complex?

A stack of flat sacs

What is the function of the Golgi complex?

Temporarily stores chemical substances formed in the ER

What are vacuoles?

Large sacs which store chemical substances

What are vesicles?

Small sacs which store chemical substances

What are lysosomes?

Membranous sacs

What do lysosomes contain?

Hydrolytic enzymes

Where are lysosomes made?

Formed from saccules of the Golgi Complex

What is autolysis?

Programmed cell death

What are mitochondria?

Organelle which produces ATP (energy) through cellular respiration

What is cellular respiration?

Cellular process which turns glucose and oxygen into energy for cells

What are centrioles?

Involved in cell division (only in animals)

Where do you find centrioles?

in the cytoplasm of the cell

What are the two organelles for motion?

Flagella and Cillia

What is the flagella?

A tail that is used for movement of cells

What are cilia?

Short hairs that are used for movement of cells

Where are two common places that cilia is found?

In the respiratory tract and the fallopian tubes

What is Interphase?

The stage of the cell cycle when a cell grows, duplicates its DNA, and prepares for cell division

What is the G1 phase of interphase?

The first growth phase where the cell grows, synthesizes proteins, and produces organelles

What is the S phase of interphase?

The synthesis phase where the cell replicates its DNA

What is the G2 phase of interphase?

The second growth phase where the cell continues to grow and form mitotic structures

What are the four steps in the mitotic phase?

Prophase, Metaphase, Anaphase, and Telophase.

What is prophase?

The first stage where DNA coils up into chromosomes and a mitotic apparatus forms

What is metaphase?

The second stage of mitosis where chromosomes line up in the middle

What is anaphase?

The third stage of mitosis where sister chromatids separate and move towards opposite sides of the cell

What is telophase?

The last stage where the cell divides into two cells, the DNA uncoils and the spindle fibers disappear

What is cytokinesis?

The division of the cytoplasm

How often do skin cells, blood cells, and cells lining the alimentary canal divide?

Divide continuously through life

What is the alimentary canal?

The entire passage through which food passes from the mouth to the anus, including the esophagus, stomach, and intestines

How often do liver and kidney cells divide?

They divide as needed

How often do muscle and nerve cells divide?

They lose their mitotic ability

What does Amitotic mean?

Can not divide

What are the two types of abnormal cell division?

Hyperplasia and Neoplasia.

What is hyperplasia?

An increase in the number of cells

What is a neoplasm?

Uncontrolled growth of cells (a tumor)

What are malignant tumors known as?

Cancers

What is the end result of meiosis?

Production of haploid sex cells (gametes) : sperm and ova

Where does meiosis occur?

In the reproductive organs

What does Karyokinesis mean?

The division of the nucleus during cell division

What does soma mean?

Body

What is a karyotype?

An organized picture of ones chromosomes