ORGANELLES

Question 1

Nucleus (nuclear envelope, chromatin)

Answer 1

-carries the genetic instructions in DNA
-on the outside there is nuclear envelope with pores; RNA is made in the nucleus and it leaves through these pores
-inside -> nucleolus and it contains chromatin fibers made up of complex of DNA plus histones (circular proteins); chromatin fiber is super coiled to make one chromosome

Question 2

Ribosomes

Answer 2

-area where protein synthesis (proteins are made)
-they are found attached to rough ER or they can float freely in the cytoplasm
-DNA transfers coded information to mRNA (messenger) and from the nucleus the mRNA leaves through the pores and binds to a ribosome where genetic information is translated into a protein (amino acid/polypeptide chain)

Question 3

Endoplasmic reticulum (smooth ER and rough ER, transport vesicles)

Answer 3

• one of the main manufacturing sites in a cell and there are two types

-rough ER -> has ribosome in them; mRNA goes here to make proteins. two protein types made are membrane proteins and secretory proteins (packaged into transport vesicles that are pinches off from the ER)
-rough ER is found in places where you secrete.

-smooth ER -> no ribosome; they make lipids
-you find smooth ER where steroids are made and where you detoxify drugs and poison (sex organs and liver)

Question 4

Golgi apparatus

Answer 4

-the shipping and receiving center of the cell; it gets products from the ER like proteins or products can be shipped out to other organelles in the cell or are secreted out through the plasma membrane

Question 5

Lysosomes

Answer 5

-are only found in animal cells
-digest food on the level of a cell through hydrolysis
-recycling damaged organelles
-kills bacteria

Question 6

Vacuoles (in plants and animals)

Answer 6

→contractile vacuole → contracts and squeeze things out; EX: found in paramecium (protist) when the vacuole gets too full it contracts and squeezes out excess water → continuous

→ central vacuole → found in plant cells

Question 7

Mitochondria

Answer 7

-double membrane, and have their own DNA (reproduce themselves)(no other organelles have this)
-provide cellular energy
-derived from formerly free living bacteria (early on in the history of life they were their own things and then cell engulfed them)
-have their own ribosomes -> make protein
- in animal and plant cells
-function: site of cellular respiration -> taking glucose and breaking it down with the help of oxygen to make ATP + CO2 + H2O
-have folds inside = more surface area = more ATP
-a lot found in muscle cells; warm blooded have more mitochondria

Question 8

Chloroplasts

Answer 8

-double membrane, and have their own DNA (reproduce themselves)(no other organelles have this)
-provide cellular energy
-derived from formerly free living bacteria (early on in the history of life they were their own things and then cell engulfed them)
-have their own ribosomes -> make protein
-found in plants and algae (protists)
-function: site of photosynthesis; taking energy from the sun and converting it into chemical energy (glucose)
-main pigment responsible for doing this is called chlorophyll (green)

Question 9

Cytoskeleton (microtubules, cilia and flagella)

Answer 9

-a network of hollow tubes
-function: helps maintain the cell shape; it also anchors the organelles and move them around
-how? It goes along tracks which are made from microtubules
-microtubules -> tiny little hollow tubes made of proteins; can form cilia and flagella
-cilla -> many short fibers EX: help paramecium to swim
-flagella -> long single fibers EX:how sperms swim