Control That Cell

Question 1

Apoptosis

Answer 1

Cell suicide.

Cancer cells are insensitive to this

Question 2

The plasma membrane

Answer 2

Hydrophilic head

Hydrophobic

Question 3

Membrane proteins

Answer 3

Immunological identity
Facilitate transport of some substances
Some are enzymes
Receptors for some hormones

Question 4

Facilitated diffusion

Answer 4

Carrier protein specific to a substance transports it across the membrane
Eg. Glucose
Eg. Amino acids.

Question 5

Bulk transport across cell membrane

Answer 5

Into cell= endocytosis
Eg. Phagocytosis
Out of cell= exocytosis

Question 6

Ribosomes

Answer 6

Are made of protein
Assemble proteins from RNA
Assemble all the proteins needed by the cell

Question 7

Endoplasmic reticulum

Answer 7

Two types:
Rough and smooth
Rough: studded with ribosomes, produces proteins for transport
Smooth: synthesises lipids and steroid hormones, detoxify some drugs

Question 8

Golgi apparatus

Answer 8

Stack of membranous sacs
Storage, package and shipping department
Stores proteins in secretory granules
Releases them by exocytosis
Larger in cells that synthesise and export protein

Question 9

Lysosomes

Answer 9

Secretory vesicle from Golgi Apparatus 
Isolated environment for potentially dangerous materials 
Has lots of enzymes to break down 
-organelles 
-bacteria
-large organic molecules

Question 10

Cytoskeleton

Answer 10

Made of protein fibres, TWO types 
1. Microfilament 
>structural support. Smallest fibres
2. Microtubules 
>allow movement within cell. Become spindle fibres in division.make up structure of cilia and flagellum. Taxanes (cancer drug) act on these so they can no longer work

Question 11

Nucleus

Answer 11

Contains DNA
Directs all cell metabolic activity
23 somatic pairs, one from mum one from dad

Question 12

Human karyotype

Answer 12

23 somatic pairs

One sex chromosomes (X&Y)

Question 13

The cell cycle

Answer 13

Stem cell>cycles of division>organ or tissue>death

Damaged or worn out cells> die and others undergo mitosis to replace it

Question 14

Phases of cell division

Remember here there is apparently only two

Answer 14

Interphase: cell growth
Mitosis: division

Question 15

Anti-cancer drug methods

Answer 15

Deleting ended pool of nucleotides
Inhibiting needed enzymes in the cell
Hanging DNA structure (unwinding it or breaking the strands)

Question 16

Rate of cell division

Answer 16

May lead to cancer
Rate is controlled by nucleus> loss of control or checks>cancer
Faster dividing=more chance of cancer(more chance of mistake)

Question 17

Controlling cell division (2 ways)

Answer 17

Polymerase>checks, edits and executes
Caps> on the ends of telomeres. Shorten with divisions>cancer replication is fast but should not last (teleomeres shorten) BUT unfortunately cancer cells have a highly active enzyme that repairs the caps.

Question 18

Genes that regulate cell division (3)

Answer 18

Proto-oncogenes
Purpose= promote normal cell growth
Mutation= become oncogenes> uncontrolled cell growth> cancer
Tumour-suppressor genes
Purpose= prevent cell proliferation
Mutation= can’t prevent proliferation>cancer
Apoptotic genes
Purpose= promote or suppress cell death
Mutation= cells won’t kill self if cancerous

Question 19

Different genes are active in different types of cells

Answer 19

Different cell=different purpose= different protein needed
Genes are inactive while bound to a certain protein
The gene needs to be activated by an enzyme (removed from protein) before the ribosome will read its message

Question 20

Tissue types (4)

Answer 20

Muscle 
Epithelial 
Nerve
Connective 
MENC

Question 21

Muscle

Answer 21

Voluntary/ skeletal (multi-nucleic)
Long fibres (30cm up to), striated, must be stimulated by nerves, gross motor movement.
Smooth muscle
Lines vessels and organs, squeeze contents, non striated, not voluntary, regulates lumen
Cardiac (mono-nucleic usually)
Striated, cells branch, cell-cell connections at intercalated discs for contraction, involuntary.

Question 22

Epithelial

Answer 22

Covers external body and internal linings
Two types: simple and stratified
Three functions: absorption, protection and secretion

Question 23

Simple epithelium

Answer 23

Three classifications: squamous, cuboidal and columnar
Squamous;
Thin and smooth= fast DIFFUSION rate. Lines alveoli, heart vessels,blood vessels etc
Cuboidal;
Secretion, absorption, excretion eg. Line the kidney tubles
Columnar;
Lines many organs with function specific adaptations eg. Microvilli of the stomach or cilia in the trachea.

Question 24

Stratified epithelium

Answer 24

Several layers of different shapes
Lower layers undergo division to push surface layers up
Prone to cancer> fast division
Can be keratinised (skin, hair, nails)
Or not keratinised (GI tract lining, vaginal lining)

Question 25

Nerve

Answer 25

Two types
Neurones;
Excitable, they are stimulated by nervous transmissions. Initiate, receive and conduct information
Glial cells;
Not excitable, they support neurones. (Nourish, immune function, support eg. Myelin sheath.

Question 26

Connective

Answer 26

Connect epithelium to rest of body
Not exposed externally
Various appearance and function 
Cells embedded in a fluid matrix, the matrix makes up most of the volume. 
3 types: Proper, Fluid and Supporting

Question 27

Connective tissue types

Answer 27

Proper;
LOOSE loose open frameworks (areola and fat)
DENSE dense frameworks, regular, irregular and elastic
Fluid;
BLOOD
LYMPH
Supporting
BONE, solid, crystalline matrix
CARTILAGE, rubbery matrix. Hyaline cartilage, elastic cartilage, fibro cartilage

Question 28

Connective tissue functions

Answer 28

Framework for the body 
Supporting and interconnecting the body 
Transport nutrients for the body 
Defend the body 
Store energy

Question 29

Cells in connective tissue (5)

Answer 29

-Fibroblasts;
Secrete matrix (collagen, elastin fibres)
Large and irregular shaped 
-Adipocytes;
Abundant in adipose tissue 
Fat cell containing lipid droplet
-Macrophages;
Engulf pathogens and diseased cells 
Mast cells;
Involved in inflammation 
-Blood cells;
Red and white