Structure

Question 1

What is an eukaryotic cell?

Answer 1

It is a membrane bound cell with nucleus and chromosomes present and characterised with other membrane bound organelles

Question 2

What is a prokaryotic cell?

Answer 2

It is a cell which belongs to the prokaryotes kingdom,know for the lack of nucleus and membrane bound chromosomes

Question 3

What is a nucleus?

Answer 3

Largest nuclear organelle which is a double membrane surrounded by nuclear envelope which is pores which allows substances e.g RNA to move between nucleus and cytoplasm
Contains chromosomes made protein bound linear DNA
Having the genetic material of the cell

Question 4

What is a nucleolus?

Answer 4

Largest structure in nucleus be at know for being the site of the synthesis of ribosome

Question 5

What is the mitochondrion?

Answer 5

Is a double membrane and has an inner membrane which is folded to form cristae and inside of it there is a matrix containing its own enzymes to create respiration
Function:site of aerobic respiration which means glucose and other molecules are broke down to produce ATP through multiple chemical reactions.

Question 6

What is RER?

Answer 6

a series of flattened sacs called
cisternae containing different range of enzymes.Covered in ribosomes enclosed by a membrane,RER folds and processes proteins made on the ribosomes.

Question 7

What Is SER?

Answer 7

A system of membrane bounds sacs process and produces lipids and carbohydrates
Synthesis of steroids(lipids hormone)

Question 8

What is the difference between SER and RER?

Answer 8

RER has ribosomes and makes protein which SER does not

Question 9

What is Golgi apparatus?

Answer 9

Series of fluid filled flattened and curved sacs with vesicles surrounding the edge
Function:processes and packages protein and lipids and also lysosomes

Question 10

What is a ribosome?

Answer 10

Intercellular structure composed of 2 sub units (RNA and protein)and are the site of protein production.
No membrane

Question 11

What are lysosomes?

Answer 11

Are vesicle containing powerful digestive enzymes such as protease these digest large molecules into soluble molecules,bound to a single membrane
Breaks down unwanted cells.
Enabling the cell to recycle components and manage cellular waste

Question 12

What is a cell wall?

Answer 12

Rigid outer covering made out of cellulose or peptidoglycan
Give cell structure

Question 13

Cell/plasma membrane what is that?

Answer 13

Lipid bilayer contains protein in/on cell
Regulates movement of substances in cell

Question 14

(1)Describe the pathway to how an enzyme is secreted

Answer 14

Inside nucleus there is DNA which contains genetic code for enzyme and corresponding is activer when cell needs enzyme

Question 15

(2)Describe the pathway to how an enzyme is secreted

Answer 15

Transcription:gene is activated and transcended in a mRNA molecule which carries genetic instructions for building the enzyme

Question 16

(3)Describe the pathway to how an enzyme is secreted

Answer 16

mRNA PROCESS:molecule goes thru moderations like adding a cap and tail to become a mature mRNA.

Question 17

(4)Describe the pathway to how an enzyme is secreted

Answer 17

Translation:ribosomes in cell read the mRNA and build the enzyme by linking amino acids together

Question 18

(5)Describe the pathway to how an enzyme is secreted

Answer 18

Protein folding:in the cytoplasm,the newly formed enzyme starts to fold into its functional shape

Question 19

(6)/(7)Describe the pathway to how an enzyme is secreted

Answer 19

RER:where enzymes are made, moves to the Golgi apparatus for additional processing and sorting
Golgi:moves here for additional processing and sorting

Question 20

(8)Describe the pathway of how an enzyme is secreted from a cell

Answer 20

Vesicles formation: golgi packages the enzymes into vesicles

Question 21

(9)Describe the pathway of how an enzyme is secreted from a cell

Answer 21

Secretion:vesicles move to the cell’s membrane and release enzyme through a process (exocytosis)

Question 22

(10)Describe the pathway of how an enzyme is secreted from a cell

Answer 22

Enzyme function:outside it can catalize specific reactions in the cells environment

Question 23

Why are there so many folds?

Answer 23

To increase the S.A of cell

Question 24

What are the prokaryotes and what are the differences between eukaryotic cell?

Answer 24

Smaller than euk(mitochondrion can’t fit as it is to big)
-Cell wall in prokaryotes contain murein(type of glycoprotein).
-smaller ribosomes(70s compared to 80s in euk)
-Lack of nucleus (plasmids are lose in cytoplasm)
-cytoplasm lacks membrane bound organelle.
Example:bacteria cells and cyanbacteria ,archea

Question 25

What is a centriole?

Answer 25

are hollow cylinders containing microtubules arranged at right angle to each other, involved in producing spindle fibres for cell division.

Question 26

What is chloroplast structure?

Answer 26

Stroma(liquid substance)
is a alkaline, aqueous fluid which is protein rich and is present within the inner membrane of the chloroplast.
In light independent reaction

Lamella-play a role in light dependent reaction slowing chemicals to pass between grana

Thylakoids system
is a collection of membranous sacks called thylakoids. The chlorophyll is found in the thylakoids and is the sight for the process of light reactions of photosynthesis to happen.

Granum:stakes of thylakoids

Intermembrane Space – It is usually a thin intermembrane space about 10-20 nanometers between inner and outer membrane

Inner,outer membrane which is permeable to small molecule and ions
Lamella:connected to the thylakoids

Question 27

Explain the hormone secretion from nucleus to cell membrane.

Answer 27

-In the nucleus there is genes which contains instructions to produce a hormone and it is the actived and transcripted into a Messenger RNA and now it goes thru various moderations like adding a cap and a tail now ready for export from nucleus to cytoplasm through the pores
-In cytoplasm the mRNA binds to ribosome to read it and assembles corresponding protein(hormone)
-it is then transported to the Golgi apparatus going through moderation and processes like adding a sugar molecule to be it processed and package them into Vesicles for transport and move towards cell membrane via endomembrane system
-the vesicles fuse with cell membrane through releasing hormone into bloodstream to interned target cell or tissue.

Question 28

What is tonoplast?

Answer 28

Central membrane surrounding the vacuole(stores salts,minerals pigment and protein,helps maintain water balance by pushing cytoplasm toward cell wall) acts as a barrier controlling substances entering and exiting the vacuole

Question 29

What is a protoplast?

Answer 29

-A cell with no cell wall
-Often from backeria or plants
(By removal of cell wall)
-Useful in genetic studies and excitements as it allows easy manipulation to genetic code

Question 30

What factors affect the fluidity and permeability of cell membrane

Answer 30

Temperature:the phospholipids bilayer become more fluid of exposed to high temperatures

Lipid composition:unsaturated fatty acids tend a kink to prevent it to be more fluid whilst saturated tend to have kink making them to be fluid

Chloresterol:the increase,reduces the cell membrane fluidity.

Molecule and ions
Alcohol or ions(calcium) can disrupt the cell membrane integrity and fluidity.

Ions strength:higher salt concentration it can denature proteins in the cell membrane, altering their structure and function affecting the transport and signaling.

Question 31

What are other factors a affect the permeability of cell membrane?

Answer 31

Lipids raft
Cell membrane protein
Membrane asymmetry

Question 32

Which organelle doesn’t contain nuclei acid?

Answer 32

Golgi

Question 33

What does the nucleus contain?abd difference in rna and dna?

Answer 33

Genetic information of cell
And nucleoplasm which contains nucleotides and enzymes needed for DNA and RNA synthesis (both have genetic information but RNA is a single stranded molecule with shorter chain of nucleotides,DNA is double stranded with longer chain.)

Question 34

What is chromatin?

Answer 34

it is DNA coiled around protein (histones) and this form chromosomes.
And DNA in chromosomes is linear,so they aren’t joint to form a loop.

Question 35

Why is the chromosomes not visible in when seen through a microscope?

Answer 35

In mitosis chromosomes become highly condensed(visible) especially in metaphase.

Question 36

What are starch granule?

Answer 36

Is the end product of photosynthesis carbohydrate glucose can be converted into polysaccharide starch stored as starch granule.

Question 37

Why is there a loop of DNA in chloroplast?

Answer 37

Contains gene for some of the proteins needs for photosynthesis.

Question 38

What does cell sap contain

Answer 38

dissolves sugars,mineral salts and amino acid
Some may contain other molecules like in plants can contain poisonous chemicals to deter herbivores
-in flower it contain coloured pigment attracting pollinators

Question 39

Why does the cell sap have low water potential?

Answer 39

Because of the high amount of dissolved sugars and mineral ions
So water moves in by osmosis in vacuole producing a high hydrostatic pressure ,cytoplasm presses against the cell wall so cell is now turgid
Important for plant that don’t have a woody stem (softer) or don’t a significant secondary growth.