Post-test questions. 1. What does the cell theory state?

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3 Post-test questions 1. What does the cell theory state? All living things are made up of cells The cell is also the functional unit of life All living cells come from pre-existing cells 2. What are cells? The cell is the basic unit of life; the smallest structure capable of performing all the functions necessary for life.

4 Cells are specialized in structure and function according to its job e.g. nerve cell transmits electrical response e.g. muscle cells are able to contract and shorten e.g. red blood cells do not contain a nucleus and therefore they cannot divide. Additionally, their small size allows them to fit into tiny vessels

5 Post-test questions 3. What is the main difference between prokaryotic and eukaryotic cells? Prokaryotes lack a nucleus as well as membrane enclosed structures (e.g. bacteria); whereas eukaryotes have a nucleus and possess membrane enclosed structures

6 1. pro = before 2. karyotic = nucleus 3. These were the first cells. 4. They were primitive, small, had no defined nucleus (no nuclear membrane), and no membrane bound cell organelles. 5. They had ribosomes

7 1. eu = true 2. karyotic = nucleus 3. These are modern cells. 4. They have a nucleus and membranebound organelles. 5. They are much larger (up to 1000X larger).

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11 4. What is an organelle? Small structures within a cell that have a specific structure and function

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13 Structure Composed of a bi-layer of phospholipids with proteins embedded in it

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15 Function holds cell together and gives shape regulates the movement of substances in and out of the cell

16 Nuclear membrane Nuclear pore Nucleolus Chromatin Nucleoplasm

17 Structure: Dark granule in center of cell Surrounded by a double membrane called the nuclear envelope/membrane

18 Functions: Controls cell activities through protein synthesis Contains genetic info Directs cell division Site of DNA replication and transcription

19 Structure small, dark spot in nucleus Made up of RNA No membrane Function makes rrna, which then make ribosomes

20 Structure: a double membrane made of phospholipids which has nuclear pores

21 Function Separates nuclear material from cytoplasm Pores allow RNA and proteins in & out of nucleus

22 1. Densely coiled DNA wrapped around histone proteins. 2. Is condensed into chromosomes before cell replication.

23 This is the cytoplasm of the nucleus

24 Structure double membrane of phospholipids inner membrane is very folded =CRISTAE (increased surface area) fluid in between = MATRIX has its own DNA

25 Mitochondria are used to convert the chemical energy in food to ATP

26 Function: powerhouse makes energy (ATP) for the cell in a process called CELLULAR RESPIRATION C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP Cristae (inner folds) provides more surface area for enzyme reactions to make ATP

27 Structure membrane channels running from the nuclear envelope throughout cytoplasm. It is a transport system. 2 Types:

28 Has attached ribosomes. Usually connected with the nuclear membrane. Ribosomes make proteins and then place them in the rer The rer packages proteins in a vesicle and sends them to the Golgi Body.

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30 SMOOTH ER: Has no attached ribosomes. Makes lipids and steroids. Also detoxifies harmful material or waste products You ll find a lot of ser in liver cells and glands that make hormones.

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32 Structure small, dense granules made of rrna & protein No membrane 2 subunits (large & small)

33 Function site of protein synthesis (translation) Usually attached to rer so proteins can be easily exported Can be free in cytoplasm -proteins not exported

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35 Structure Free floating group of ribosomes (aka Polyribosome) Function makes large proteins (faster) with a single mrna molecule

36 (or golgi apparatus or golgi complex) Structure stacks of flattened sacs surrounded by vesicles Function Collects, sorts, packages and distributes materials modifies proteins and lipids from ER

37 DNA copies a gene as RNA RNA moves through pore and attaches to ribosome to make protein Protein put into RER, then sent to Golgi in a vesicle Golgi modifies protein, stores it until needed, and sends it to plasma membrane in a vesicle. Protein released at the Plasma Membrane via exocytosis

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39 Structure Small, membranous (bilayer) bound sac usually made by Golgi body Function Storage sac (temporary storage) ex. H 2 O, food, digestive enzymes, hormones. 2 types: Transport vesicle: moves substances from ER to Golgi Secretory vesicle: moves substances from Golgi to cell membrane

40 Structure large vesicle (but small in animals) and typically one large in plants Membranous sacs Function Long term storage of H 2 O with dissolved sugars and salts Plant cell Vacuole

41 Structure Double membraned vacuoles with hydrolytic (digestive) enzymes Function Hydrolysis! destroys harmful substances can kill the cell if it breaks open - suicide sacs many in white blood cells Also, breaks down organelles that are not working anymore in tadpoles destroys their tails in human embryos destroys webbing between fingers

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44 LYSOSOME ANIMATION

45 series of protein fibres in the cytoplasm Maintains cell shape Monorail to transport organelles around the cell Assemble and disassemble as needed Made up of: 1. Microfilaments 2. Microtubules 3. intermediate filaments

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47 aka actin filaments Long & thin protein fibres Anchored to the plasma membrane Organelles move around the cytoplasm on these

48 Gives structure and support to cell membrane Actin interacts with motor molecules such as myosin. In the presence of ATP, myosin pulls actin along Example: muscle cells

49 Structure Largest fibre Cylinder shaped & made of tubulin (protein) Function Anchor for organelles and monorail for organelle movement Used to make cilia, flagellum & centrioles

50 Structure Intermediate size between actin filaments and microtubules made of keratin Function Keeps the nucleus in place Cell-cell junctions, such as those holding skin cells tightly together

51 Structure Watery gel between cell membrane and nuclear envelope Contains water with dissolved salts, proteins & other organic compounds Function Support & suspend organelles Provide water allows diffusion to occur in cells

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54 Structure Double membrane of phospholipids inside stacks of discs called GRANUM contain: their own DNA ribosomes enzymes

55 Function photosynthesis (light energy converted into chemical energy) ATP + 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 Granum= contains chlorophyll which traps solar energy

56 Structure Tough, rigid outermost wall made up of cellulose (very strong)

57 Function maintains cell shape and skeletal support