cells

Question 1

function of the nucleus

Answer 1

• the genetic control center of cellular activity

Question 2

function of the endoplasmic reticulum

Answer 2

ER synthesises steroids and other lipids, detoxifies alchohol and other drugs and manufactuers all membranes of the cell

Question 3

rough ER

Answer 3

• produces phospholipids and proteins of the plasma membrane nd synthersizes proteins that are either packaged in organelles such as lysomomes or secreted from the cell

Question 4

smooth ER

Answer 4

• detoxifies and proliferates drugs

Question 5

ribosomes

Answer 5

• read coded messages
• assemble amino acids into proteins specified by the code
• attach to rough ER when they make proteins

Question 6

golgi complex

Answer 6

• recieves and modifies newly syntherzied polypeptides, syntherzies CHO, adds CHO to gycoproteins and packages cell products into golgi vesicals

Question 7

golgi vesicals

Answer 7

• becomes secretory vesicals and carry cell products to apical surface for exocytosis or become lysomes

Question 8

lysosomes

Answer 8

contain enzymes for intracelluar digestion, autophagy, programmed cell death and glucose mobilization

Question 9

mitochondria

Answer 9

ATP synthesis

Question 10

centrioles

Answer 10

form mitotic spindle during cell division; unpaired centrioles form basal bodies of cilia and flagella

Question 11

microvilli

Answer 11

increase absorpitive surface area; widespread sensory roles

Question 12

flagellum

Answer 12

sperm motility

Question 13

cilia

Answer 13

move substances along cell surface

Question 14

microtubules

Answer 14

enable motility of cell parts

Question 15

plasma membrane

Answer 15

it defines the boundries of the cell, governs its interactions with other cells, and controls the passage of materials into and out of the cell

Question 16

membrane proteins

Answer 16

• integral proteins
• transmembrane proteins
• peripheral proteins

Question 17

functions of membrane proteins

Answer 17

• receptors
• second messenger systems
• channel proteins
• enzyme
• gated channel
• cell adhesion molecules
• cell identity markers

Question 18

filtration

Answer 18

movement of material without the aid of a carrier protein

Question 19

simple diffusion

Answer 19

movement of water and solutes through a selectivley permerable membrane as a result of a different gradient

Question 20

osmosis

Answer 20

net flow worth of water through a selectivley permable membrane driven by either a difference in solute concentration or a mechanical force

Question 21

facilitated diffusion

Answer 21

transport of particlas through a selectivley permeable membrane down their concnetration gradient by a carrier that does not directly consume ATP

Question 22

active transport

Answer 22

transport of particlas through a selectivley permeable membrane up their concnetration gradient by a carrier that does consume ATP

Question 23

endocytosis

Answer 23

vesicular transport of particals into a cell

Question 24

exocytosis

Answer 24

process of eliminating material from the cell

Question 25

protein synthesis

Answer 25

when a gene is activated a MRNA is made of the gene. the MRNA migrates from the nucleus to the cytoplasm where is serves as a code for assembling amino acids in a particular order to make a protein

Question 26

transcription

Answer 26

RNA polyermarse binds to the DNA and assembles the RNA. it reads the base sequences from DNA and makes a corresponding RNA.

Question 27

translation

Answer 27

``` 3 steps: 1- initiation 2- enlongation 3- termination 4- making proteins for packaging or export ```

Question 28

initiation

Answer 28

mRNA passes through a nucelar pore into the cytosol and forms a loop. A ribsome binds to the subunit and slides along the mRNA until it finds a start codon (AUG). the initiator tRNA with the matching anticodon pairs with the start codon embraces the mRNA groove reading its bases.

Question 29

elongation

Answer 29

the next tRNA arrives and binds with the A site of the ribosome and continues to make a chain of amino acids as the ribosomes slide along the bases reading the code.

Question 30

termination

Answer 30

when the ribosome reaches the stop condon its A site binds a protein called a release factor instead of tRNA. The release factors causes the finished protein to break away from the ribosome and go off into the cytsol. The ribsome then dissociates into its two subunits

Question 31

making proteins for packaging ir export

Answer 31

is a protein is to be packaged into a lysosome or secreted from the cell the ribosome docks onto the rough endplasmic reticulum. The ER modifies this protein and packages it into transport vesicles.

Question 32

G1 (first gap phase)

Answer 32

- cell synthesizes proteins, grows and carries out preordained tasks for the body - accumalte materials needed to replicate DNA

Question 33

synthesis phase

Answer 33

in which the cell makes a dupilcate copy of the centrioles and all of its nuclear DNA. The two identical sets of DNA molecules are then available to be divided up between daughter cells at the next cell divison

Question 34

G2 phase

Answer 34

- cell growth, makes more organelles, finishes replicating centrioles, and synthesizes rzes enzymes that control cell division

Question 35

M miotic phase

Answer 35

cell replicates its nucleus and then pinches in two form two new daughter cells

Question 36

mitosis functions

Answer 36

- development of an individual - growth of tissues and organs - replacement of cells that die - repair of damaged tissues

Question 37

prophase

Answer 37

chromsomes condense and nucelar envelope breaks down. Spindle fibre grows from centrioles, centrioels migrate to opposite poles of cell

Question 38

metaphase

Answer 38

chromosomes lie along midline of cell. Long microtubules reach out from each centriole to the chromsomes and shorten.

Question 39

anaphase

Answer 39

centromeres divide into 2. Spindel fibres pull sister chromatides to opposite poles of cells.

Question 40

telophase

Answer 40

chromsomes gather at each pole of cell. Chromatin decondenses. New nuclear envelope appears at each pole. new nuceoli appear in each nucleus. Miotic spindel vanishes.

Question 41

DNA structure

Answer 41

is a long threadlike molecule with diameter of 2nm. - double helix composed of a back bone os phosphate groups alternating with the sugar deoxyribose - DNA is a polymer of nucleotides which consists of sugar and a phosphate group

Question 42

Chromosome structure

Answer 42

DNA is complexed with proteins called chromatin which occurs as long filaments called chromosomes

Question 43

differene between RNA and DNA

Answer 43

``` DNA - deoxyribose - ATCG - 2 double helix - functions in nucleas cannot leave - codes for synthesis of RNA and protein RNA - ribose - one - leaves nucleas functions mainly in cytoplasm - carries out the instructions in DNA assembles proteins ```