Eukaryotic cell ultrastrucute

Front

structure of nuclues

Back

1. 1. nucleus is the largest organelle, spherical or ovoid in shape

2. 2. surrounded by a double membrane known as the nucluear envelope which is perforated with pores known as nucleus pores

3. 3. the outer membrane of nuclear envelope is continuous with the ER

4. 4. inner membrane of the nuclea envelope is in contact witht he contents of the nucleus

5. 5. there can be more than one nucleolus in the nucleoplasm

6. 6. nearly all the cells dna is found here organised into chormosones

7. fucntion:

1. 1. controls cellular activities by regulating protein and eznyme syntheis

2. 2. nuclear division is the basis of cell division

3. 3. nucleolus is responsible for synthesis and partial assyembly of ribosmomes

Front

cell surface membrane

Back

1. 1. a phsopholipid bilayer with hydrophobic tails on the interior and hydrohphobic heads on the exterior

2. 2. each phospholipid is made up of a glycerol moleucle attatched to two fatty acid chains and a phosphate group

3. 3. contians cholesterol , glycoproteins and glycolipids nad transport protiens

4. fucniton:

1. 1. partially permeable membrane

2. 2. prevents most water solubel substsnces from leaving/entering the cells

3. 3. acts as a barrier between cytoplasm and environtment

Front

centrioles

Back

centrioles are in ANIMAL CELLS ONLY

1. 1. cynlindrical like structures composed of microtubules

2. 2. each centriole is made up of 9 microtubule triplets arranged in the shape of a cylinder

3. 3. 2 centrioles make up a centrosome

4. 4. found in pairs only in animal cells positioned in the cytoplasm outside but near the nucleus/ as single structures at the base of cillia and flagella

5. fucnitons:

6. 1. produces spindle fibers that attatch to chormosones and separates them during cell division

7. 2. it is involved in the formation of cillia and flagella

Front

ribosomes

Back

1. 1. the smallest organelle,

2. 2. about 20 nanometers in size

3. 3. has no membranes

4. 4. made up of protein and ribonucleic acid

5. 5. each ribsome comprises of 2 sub unita, one large and one small

6. 6: it is attatched to the RER or as free ribsomes in the cytosol

7. 7: its the site of protein synthesis

Front

endoplasmic reticulum

Back

1. 1. originates from the outer membrane of the nuclear envelope

2. 2. consists of a network of membranous tubes or sacs called cisternae

3. 3. smooth er : lacks ribosomoes, more tubular

4. 4: rough er: ribosomes present on its surface

5: smooth er function : synthesis lipids esp membrane phspholipids and steroid hormones

6: rough er function : site where proteins are synthesised and transported via cisternae or packaged in membranous /ER vesicles

Front

golgi apparatus

Back

1. 1. consists of a stack of flattened membrane - bound sacs called cisternae

2. 2. it is continually being fromed at cis face by fusion of a vesicle from the ER and continually budded off at the transface where vescicles are pinched off

3. 3: fucntion :

4. - chemically modifies, sorts and transports molecules within it for secretion across the cell membrane or for delivary to the other parts of the cell

5. - lysosome formation

Front

lysosome

Back

1. 1. small spherical vesicles

2. 2. larger in plant cells

3. 3. bound by a single membrane

4. 4. formed from GA

5. 5. contain a concentrated mixture of hydrolytic digestive enzymes

functions:

1. 1. digestion of materials taken in by cells

   2. 2. autophagy of worn our or improperly functioning organelles

   3. 3. autolysis : self digestion of a cell by the release of lysosome contents within the cell

Front

mitochondrion

Back

1. 1. a rod shaped/ cylindrical shaped organellle

2. 2. bound by a double membreane, outer and inner membrane is separated by inter- membrane spaces

3. 3. outer membrane is smooth and continous boundry

4. 4. inner membrane is extensively folded to form cristae that project into the interior/matrix

5. 5: within the matrix, hereditary materials and ribosmoes can be found

6. fucntion : involved in cellular respiration to release energy

Front

cell wall

Back

1. 1. in plant cells only

2. 2. surrounds the plant cell, external to cell surface membrane

3. 3. consists of predominantly cellulose

4. 4. cell wall materials are strong YET permeable to allow free passage of substances into and out of cell

5. function: provides mechanical support and protective layer

Front

chloroplast

Back

1. 1. in plant cells only

2. 2. large organelles (after large central vacuole and nucleus)

3. 2. bound by a double membrane

4. 3. outer membrane is smooth and continuous

5. 4. inner membrane gives rise to membranes called lamellae or thylakoids which extend throughout the interior

6. 5. interior of a chlorplast is a gel like matrix known as the stroma

7. 6. within the stroma, thylakoids are stacked into grana which are joined together by the intergranal lamellae

8. 6. contianst photsyhnthetic phgments called chlorplast which make chlorplast appear green

9. function: site of photosynthesis