Cell Structure And Functions

Question 0

Function of ribosomes

Answer 0

Protein synthesis

Question 1

What are the functions of the nucleolus?

Answer 1

rRNA is synthesized

Proteins and rRNA are synthesized into subunits of ribosomes to be assembled later

Question 2

Functions of the Golgi apparatus

Answer 2

Products of the rER are modified stored and shippedg

Question 3

Functions of sER

Answer 3

Diverse metabolic processes (carbohydrate metabolism)
Synthesize lipids , steroids and steroid hormones, phospholipids
Detoxify drugs and poisons
Storage of calcium ions

Question 4

What is the nuclear lamina and what does it do?

Answer 4

-A net like array of protein filaments

Maintains the shape of the nucleus by mechanically supporting the nuclear envelope

Question 5

What is the nuclear envelope?

Answer 5

Double membrane
Made of two lipid bilayers associated with proteins
Contains pores that have intricate poor complexes regulating what enters and exits the cell

Question 6

What are ribosomes made of

Answer 6

They are complexes made if ribosomal RNA and proteins

Question 7

What does the endomembrane system include?

Answer 7

The nuclear envelope, the rER, sER, Golgi apparatus, lysosomes, various vesicles and vacuoles, and the plasma membrane

Question 8

What does the ER consist of?

Answer 8

A network of membranous tubules and sacs called cisterna.

Question 10

What does the Golgi apparatus consist of?

Answer 10

Flattened membranous sacs -cisterna- stacked on each other

Question 11

What kind of ribosomes do prokaryotes have?

Answer 11

free ribosomes

Question 12

What are the functions of the nucleus?

Answer 12

direct metabolism
growth
development
reproduction by dieting protein synthesis

Question 13

vesicles

Answer 13

relatively short lived sacs enclosed by membrane

often for transport

Question 14

What are the functions of the rER?

Answer 14

protein synthesis
protein packing
protein secretion
phospholipid synthesis
glycoprotein  synthesis
synthesize transport vesicles

Question 15

What are the functions of lysosomes

Answer 15

digest old macromolecules
digest old organelles
apoptosis- programmed cell death

Question 16

what do lysosomes contain?

Answer 16

lipases break down lipids
cabohydrases break down carbohydrates
protases break down proteins
nucleases break down nucleic acids

Question 17

function of food vacuoles

Answer 17

store and break apart food in some protists

Question 18

function of contractile vacuoles

Answer 18

expel excess water in some protist

Question 19

function of the central vacuole of plants

Answer 19

• helps maintain turgidity of cells
• stores organic compounds and inorganic ions
• break down organic molecules
• store pigments
• dumping ground for toxic waste

Question 20

What is the central vacuole enclosed by

Answer 20

tonoplasts

Question 21

peroxisomes are made of?

Answer 21

• membrane enclosed sac
• sometimes a crystalline lattice appearance
• contain many enzymes

Question 22

What is the function of peroxisomes?

Answer 22

it is involved in oxidation reactions that strip hydrogen atoms from organic molecules to make double bonds and produce H2O2 (oxidases)

• contain catalases to break down hydrogen peroxide
• in some peroxisomes fatty acids are broken down into smaller molecules
• detoxify alcohols

Question 23

What are the function of mitochondria?

Answer 23

• site of aerobic cellular respiration
• food is broken down into ATP
• synthesize some proteins but most are transported from cytosol into mitochondria are moved around the cell using the cytoskeleton

Question 24

outer membrane of the mitochondria

Answer 24

smooth and permeable to many small ions

Question 25

inner membrane

Answer 25

convoluted more selective many enzymes of cellular respiration are embedded in membrane convolutions increase surface area (called cristae)

Question 26

matrix of the mitochondria

Answer 26

inner compartment, contains enzymes involved in cellular respiration

Question 27

mitochondria

Answer 27

- may fuse or split - may form a branched tubular network and divide independently of the cell - DNA is isngle circular not associated with histones

Question 28

plastids organelles in plants and protists

Answer 28

amyoplasts- store starch | chromoplasts-plastids with colored pigments other than chlorophyll

Question 29

function of chloroplasts

Answer 29

- primary function is photosynthesis - synthesize carbohydrates - synthesize amino acids

Question 30

Chloroplasts structure

Answer 30

- double membrane surrounds internal membrane system - thylakoid: internal membrane sacs, where light independent reactions occur - grana are sacs of thylakoids - stroma: semi-fluid region outside of thylakoids where light independent reactions occur - contain DNA similar to mitochondria

Question 31

endosymbiosis

Answer 31

theory that mitochondria and chloroplasts are ancient prokaryotes that took up residence in the precursors of eukaryotic cells, survived, and started to divide independently of eukariotic cells precusor

Question 32

for what reason are mitochondria and chloroplasts thought to be semi-autonomous?

Answer 32

Some of their DNA was moved into the nucleus of the host cell

Question 33

what is the evidence of for endosymbiosis

Answer 33

- there are many symbiotic relationships between prokaryotes and eukaryotes - mitochondria and chloroplasts are similar to bacteria in size and shape - both have single circular DNA not associated with histones - both have ribosomes that are like prokaryotic ribosomes - both divide independently of the host cell and like prokaryotes - both have inner membranes with enzymes and transport systems that are homologous to those found in living prokaryotes

Question 34

what is the cytoskeleton?

Answer 34

``` network of fibers throughout the cytoplasm 3 types of filaments -microtubules -micrfliaments -intermediate filaments ```

Question 35

What is the function of the cytoskeleton?

Answer 35

support movement and regulation of the cell

Question 36

proteins and their interaction of cell movement

Answer 36

interacts with the cytoskeleton and motor proteins | dynein motor proteins are responsible for bending movements of cilia and flagella, shape changes using energy of ATP

Question 37

how do cilia and flagella move?

Answer 37

shape changes using ATPone foot maintains contact while other foot release and attaches one set further, microtubule doublets held in place by cross linking proteins

Question 38

function of centrioles

Answer 38

may help organize spindle apparatus that moves chromosomes during cel division

Question 39

function of primary cilium

Answer 39

- transmit chemical and mechanical signals from the environment - the cell interior triggering signal transduction pathways that may lead to changes in cell activities

Question 40

function of microfilaments

Answer 40

- cell support, bears tension - cell division, cytokinesis division of the cytoplasm - cell movement, creeping movement - distribute things, cytoplasmic streaming, - organism movement, muscle contraction

Question 41

function of microtubules

Answer 41

- cell support, compression resisting - cell movement, part of cilia and flagella structure - involved in cell division, moves chromosomes around as spindle apparatus - organelle movement - vesicle movement

Question 42

function of intermediate filaments

Answer 42

- cell support, bear tension - cell adhesion, desmosomes, - hold organelles such as the nucleus in place - formation of the nuclear lamina that supports nuclear envelope