Eukaryotic cell

Question 1

Define a cell

Answer 1

the basic unit of life

Question 2

organelles

Answer 2

small structures inside a cell with specific function

Question 3

structure of cell membrane

Answer 3

2 layers of phosholipids, proteins

Question 4

function of cell membrane

Answer 4

what comes in and what goes out of cell

- thats why it is semi permeable

Question 5

structure of cytoplasm

Answer 5

made of a fluid (cytosol) and organelles except for nucleus)

Question 6

function of cytoplasm

Answer 6

all of the cells contents lie between the cell membrane and the nucleus

Question 7

structure of nucleus

Answer 7

membrane bound that contains DNA

Question 8

function of nucleus

Answer 8

‘control centre’ that regulates DNA & RNA actions

Question 9

structure and function of nucleus envelope

Answer 9

f- regulates what enters and exits the nucleus

s- double layer of lipids

Question 10

structure and function of nucleolus

Answer 10

f- produces RNA, which makes proteins

s- inside Nucleus, separate from DNA

Question 11

Function of DNA

Answer 11

f- info on how to make proteins

a. chromatin (unorganised DA)
b. chromosomes (organised DNA (present before cell division)

Question 12

structure of DNA

Answer 12

made of nucleotides, locked in the nucles

Question 13

structure of Endoplasmic reticulum

Answer 13

tubes and channels

Question 14

function of ER

Answer 14

transport for proteins
RER- has ribosomes
SER - no ribosomes

Question 15

Function of ribosomes

Answer 15

Make proteins

Question 16

Structure of ribosomes

Answer 16

Small circular organelles

Question 17

Structure of vacuoles & vesicles

Answer 17

Small membrane bound organelle

Question 18

Function of vacuole and vesicles

Answer 18

Storage for water, nutrients and waste

Question 19

Structure and function of lysosomes

Answer 19

F - packet of enzymes that break materials down in a cell

S - small membrane bound organelle

Question 20

Function of mitochondria

Answer 20

To produce energy for the cell, site of cellular respiration “the powerhouse”

Question 21

Structure of mitochondria

Answer 21

Double membrane bound, kidney shaped

Question 22

Function of golgi apparatus

Answer 22

Packages, labels and ships proteins out of cell

Question 23

Structure of Golgi apparatus

Answer 23

Pancake shaped, layered organelle

Question 24

Structure of cytoskeleton

Answer 24

Provide support and structure for the cell

Question 25

Structure of cytoskeleton

Answer 25

Tubules

Question 26

Structure of centrioles

Answer 26

Tubules

Question 27

Function of centrioles

Answer 27

Micro tubules that help divide the cell in cell division

Question 28

Rough ER

Answer 28

- covered in ribosomes - sheet like in appearance - prominent in cells carrying out extensive protein synthesis

Question 29

Smooth ER

Answer 29

- prominent in cells with lipid and drug metabolism | - is more tubular

Question 30

Main functions of ER

Answer 30

1. Detoxification of drugs 2. Translocation of proteins 3. Glycosylaytion of proteins 4. Assembly of lipid bilayers

Question 31

F of lysosomes

Answer 31

- stomach of cell (digests macromolecules) | - clean up crew of cell (cleans up broken organelles)

Question 32

Lysosomal enzymes

Answer 32

- work best at ph5 (so organelle creates custom pH) | - does this by pumping H+ ions from cytosol into lysosomes

Question 33

Apoptosis

Answer 33

- auto-destruct process | - lysosomes break open and kill cell

Question 34

Golgi body also known as

Answer 34

- golgi complex - Golgi apparatus - Dictyosome (plants )

Question 35

S of golgi body

Answer 35

- stack of 4-6 flattened smooth membrane bounded compartments with associated vesicles - slightly concave, polarized structure

Question 36

F of Golgi body

Answer 36

1. Protein modifications - addition of other molecules/groups to the protein to change its shape and function 2. Protein processing - cleavage of peptides to produce activated proteins 3 . Protein sorting and localisation

Question 37

Protein modifications

Answer 37

- addition of sugars (glycosylation to give proteoglycans) - + of fatty acids (productions of lipoproteins) - + of phosphate groups (phosphorylation)

Question 38

Function of proteoglycans

Answer 38

- they are are major component of the extracellular matrix, the ‘filler’ substance existing between cells in an organism - bind cations e.g sodium and water through the matrix - individual functions of proteoglycans are due to their protein core

Question 39

Protein processing

Answer 39

- many polypeptides, hormones and neurotransmitters are synthesised as inactive precursor molecules - the active form is liberated by proteolysis

Question 40

Protein sorting

Answer 40

- mammal approx 10,000 diff kinds of proteins - for a cell to work properly each one of these proteins must be localised to the correct membrane or compartment - DNA - modifying enzymes such as RNA and DNA polymerases are made on CYTOSOLIC ribosomes and then transported to the NUCLEUS - ion-channel, transporter and receptor proteins need to be localised in the plasma membrane - the process of directing each polypeptide to a particular destination - depends on the presence of sorting SIGNALS and multiple SORTING EVENTS

Question 41

Protein sorting (golgi apparatus)

Answer 41

A. Lysosomal pathway B. Constitutive pathway C regulated secretion

Question 42

Mitochondria

Answer 42

- in all eukaryotic cells - fairly large 1um diameter - have double membrane structure (envelope) - major function ATP generation - the mitochondria converts food energy e.g carbohydrates to fatty acids

Question 43

``` Mitochondrial function (Oxidative metabolism) ```

Answer 43

1. Large molecules broken down into smaller subunits 2. Numerous small molecules are converted into a few key molecules which plays a central role in metabolism 3. Oxidation to produce ATP

Question 44

ATP

Answer 44

- molecular unit of intracellular energy currency - total quantity of ATP in adult is approx 0.10mol/L - but approx 100-149 mol/L of ATP is required daily, so we only have enough for 2 minutes - so each ATP molecule is recycled 1000 to 1500 times a day

Question 45

Mitochondrial ATP synthesis

Answer 45

- The energy from the high energy electrons is used to pump protons (H+) across the inner mitochondrial membrane from the matrix and into the inter-membrane space - the protons then flow back down the gradient and this energy drives coupled ATP synthesis

Question 46

Cytoskeleton

Answer 46

- Provides supporting framework for the cell and gives the cell its particular shape - Actin filaments anchored just underneath the plasma membrane are responsible for changing the shape of the cell

Question 47

Cytoskeleton and its associated motor proteins organises and moves the cytoplasmic contents

Answer 47

- movement of organelles (microtubules) - movement of vesicles (micro tubules) - the whole cell movement is polarised and directional - movement of cells is important in development processes

Question 48

Components of cytoskeleton

Answer 48

1. Microtubules - made of tubulin - 25nm diameter - e.g mitosis, ciliia, flagella, centrioles 2. Actin filaments (microfilaments) - made of actin - 6nm diameter - e.g cytoplasmic streaming 3. Intermediate filaments - several proteins such as keratin - intermediate size, i.e 10-15nm diameter - e.g keratins in skin, hair,nails (animal horn) etc