objectives

Page 1

Cell Organelles (objective #7)

Cytoplasm: the area of the protoplasm between the nucleus

and the cell membrane

Cytosol: the fluid gel-like component of the cytoplasm made

up of mostly water

Organelles: structures within the cell that have specific

function. Only found in eukaryotic cells

Receptor sites: found in the cell membrane, allows other

materials to adhere and transfer in

Chromosomes: thread-like strands of DNA found in the

nucleus

Genes: units of hereditary instruction found in chromosomes

Chromoplast: plastid that stores orange and yellow pigments

×

Plastid: an organelle found in only plant cells

that is responsible for food production or storage. All plastids no matter the

pigment they contain have stacked internal membranes

◦

Amyloplast: colorless plastids that stores

starches

◦

Chloroplast: the one type of lasted that stores

green pigment chlorophyll. It is the site of photosynthesis

×

They are a double membrane bound organelle. The

stroma is a liquid-like substance that bathes the thylakoid membranes.

(Thylakoids: look like disks, the site of photosynthesis.)

◦

Leucoplasts: store starch

Mitochondria (only organelle with its own DNA)

×

Mitochondria: the powerhouse of the cell and

the site of cellular respiration

×

Like the chloroplast, it also has a double

membranes

Cristae

×

Side the organelles increases surface area for

chemical reactions

×

Have their own DNA

Cell wall

×

Only found in plant cells, composed of

cellulose (what fibers are made of) (also found in bacteria and fungi cells)

×

Function is to support and protect the cell

×

(objective #12) – layers between called middle

lamella and is the source of pectin (jelly)

1.

The theory of abiogenesis is the theory that

life comes from non-living sources. It was initially proposed by Aristotle as

spontaneous generation, meaning that non-living things can be transformed into

living things spontaneously. In the past, a Belgian doctor, Jean van Helmont

said that mice could be created from grain and a dirty shirt. According to

Helmont, the sweat from the shirt cause the wheat to ferment, and when it

bubbled, it transformed into mice. Also, it was believed that rotting meat

could transform into flies. There were maggots which proved that flies were

laying eggs.

2.

Spontaneous generation is a synonym of

abiogenesis

3.

Francesco Redi’s experiment

Hypothesis: because of abiogenesis rotting meat

left in sealed and unsealed jars will transform into flies

Control: sealed jars

Dependent variable: seal

Independent variable: flies

4.

Scientists to know

×

Aristotle: created the theory of abiogenesis.

He believed that fish and frogs came from the mud and that flies came from

rotting meat. The theory was accepted by scientists for almost 2000 years

×

Jean van Helmont: a Belgian doctor who believed

that mice were created from dirty and shirts and grain which supported the

theory of abiogenesis

×

Francesco Redi: an Italian physician who

experimented whether rotting meat could be turned into flies. Conclusion

disproved abiogenesis. He was considered the first “scientist”.

×

Anton van Leeuwenhoek: an expert lens maker and

a very observant scientist. His microscope was the first to reveal

microorganisms and human blood cells

×

John Needham: concluded that microbes such as

mold and bacteria came from non-living things while experimenting with beef

broth. He was repeating Redi’s experiment and supported abiogenesis.

×

Lazzaro Spallanzani: rejected abiogenesis.

After boiling the flasks longer, no microorganisms appeared.

×

Louis Pasteur: after boiling in an S-shaped

flask he received improved results finally disproving abiogenesis

×

Robert Hooke: first coined the word cell. He

noticed the rigid cell walls that surrounded the once living plant cells in

cork

×

Robert Brown: identified and named the sphere

in plant cells the nucleus

×

Theodor Schwann (animal) and Mathias Schleiden

(plants): concluded that plant and animal tissues are composed of cells. They

prepared the foundations for the modern cell theory.

×

James Hillier and Albert Prebus: designed the

first truly functional transmission electron microscope.

5.

The two major statements that comprise the cell

theory are:

a)

All living things are composed of cells. The

cell is the basic unit of organization

b)

All cells arise from pre-existing cells. Cells

do not come from non-living things

8.

Light Microscope

Electron microscope

Cell membrane

Golgi apparatus

Cell wall (plant)

Smooth ER

Nucleus

Rough ER

Cytoplasm

Mitochondria

Nucleolus

Ribosome

Chloroplast (plant)

Centriole

Vacuole

Microfilaments

9.

Structures:

a)

The mitochondria have two membranes; a smooth

outer membrane and a folding inner membrane. The fingerlike projections are in

the inner membrane are called Cristae. Special proteins called enzymes are

located on the Cristae.

b)

Chloroplasts consist of grana (granum) which

are green disks staked together. The grana are surrounded by a gel-like

substance that controls proteins, that is called stroma. This is surrounded by

the inner membrane, followed by the outer membrane.

c)

Cells are surrounded by non-living cell walls

that protect and support them. Plants may have a single cell wall, which is

referred to as the primary cell wall. Some plants are provided with extra

strength and support from what is called the secondary cell wall.

10.

Respiration

is the chemical process in which nutrients are broken down to provide energy

C6H12O6 +6O2 6CO2 + 6H2O +

energy (ATP)

Sugar oxygen carbon dioxide, water

11.

Relationships

a)

Chromosomes contain genes which determine

traits of an individual

b)

The mitochondria are the site of cell

respiration and the chloroplast is responsible for photosynthesis which are the

two types of energy

c)

The rough endoplasmic reticulum has ribosomes

attached to it. The rough endoplasmic reticulum is responsible for transporting

proteins and the ribosomes are responsible for synthesizing proteins

12.

Define

a)

Vesicles: are the small packets that are

released once the Golgi apparatus fuses to the outer membrane. This process is

Exocytosis, the means by which molecules such as hormones and enzymes are

released from cells

b)

Selectively permeable means that it is selective

of what passes through and at what time materials pass through

c)

Pectin is the sticky fluid that is in the

middle of the lamella which is the layer found between the cell walls. Pectin

helps hold the cell together.

13.

Plant

and animal cells differ in many ways. Plant cells are able to produce their own

food, which animal cells can’t do. A large part of the cytoplasm in a plant

cell consists of the vacuole, which is not as large in animal cells since they

don’t need to store as much sugar, protein or minerals for the cell because

they don’t produce their own food. Plant cells have plastids that are

associated with food production and storage which animal cells don’t have.

Plant cells are surrounded by cell walls to provide extra protection and

support.

14.

Eukaryotic cells have a true nucleus and

contain organelles. The nuclear membrane surrounds a well-defined nucleus.

Prokaryotic cells are primitive cells that don’t have a true nucleus or nuclear

membrane. An example of eukaryotic cells is plant and animal cells. An example

of prokaryotic cells is bacteria and blue-green algae.

15.

You would expect to find more amyloplasts in

potato tuber than a potato leaf because the root would contain more starch

which is stored by amyloplasts. The leaves wouldn’t contain the same amount of

starch.

16.

*assignment*

17.

Processes

a)

Cell fractionation is the process where all

fragments of a cell are separated by centrifugation. This process allows people

to receive information about the thousands of chemical reactions that takes

placed at the same time in a cell. The process consists of grounding cells into

fragments and putting them in a test tube which get spun in centrifuge. The

centrifuge is a machine that rotates at high speed to produce a force of

gravity hundreds of thousands of times higher than normal. The heaviest

structures move to the bottom and the light structures stay close to the

surface. Each layer then contains different cell parts. Each layer can be

separated and the chemical reactions can be studied.

b)

The purpose of radioisotopes is to allow

scientists to study specific chemical reactions in specific organelles. Cells

are treated with radioisotopes which are unstable chemicals that release bursts

of energy as they break down. The radioactive chemicals can then be followed

through chemical reactions.

18.

The cell membrane is a bi-lipid fluid mosaic

structure that controls the chemical environment of a cell. The cell membrane’s

three main components are lipids, proteins, and carbohydrates. The membrane

consists of two or membranes of lipids. Each lipid is described as having one

head, which faces the outer environment, and two tails which are towards the

inside. The lipids are mobile, contributing to movement within the cell

membrane.

19.

Hydrophilic means water loving and is soluble

in water. The “head” region of the lipids is hydrophilic. Hydrophobic means

water fearing and is not soluble in water. The “tail” region of the lipids is

hydrophobic.

20.

Glycoproteins are protein molecules which carry

a carbohydrate and act as special identifiers. Glycolipids are lipid molecules

that carry a sugar molecule. They provide energy. (May assist with

identification).

21.

Other

protein molecules in the cells open and close paths through the cell membrane

creating channels. Some other proteins work as receptor sites for hormones.

Another type of protein is also involved in transport. It uses cell energy to

pick up needed materials and moves them in or out of the cell.

22.

a)

Active transport is the use of cell energy to

move materials across a cell membrane against the concentration gradient

(low-high concentration). Examples of active transportation are Endocytosis and

transport pump.

b)

Passive transport is the movement of materials

across the cell membrane without using cell energy (high-low concentration).

Examples of passive transport are diffusion, facilitated diffusion, and osmosis

23.

Diffusion is the movement of molecules from an

area of high concentration to an area of lower concentration. Diffusion is

affected by temperature, pressure and concentration, and will occur until all

molecules are distributed equally in an area.

24.

Factors that influence the rate of diffusion

are concentration, temperature, pressure, mass/size (larger moves slower,) and

polarity (charges).

25.

a)

Equilibrium: a condition in which all acting

influences are balanced resulting in a stable condition

b)

Osmosis: the diffusion of water through a

selectively permeable membrane

c)

Diffusion: the movement of molecules from an

area of higher concentration to an area of lower concentration

d)

Turgor Pressure: the pressure exerted by water

against the cell membrane and the non-living cell walls of plant cells.

e)

Solute: molecules that are dissolved in water.

Salt and sugars are common solutes.

f)

Facilitated Diffusion: involves the use of cell

membrane proteins to help large or charged molecules across the cell membrane

26.

Oxygen

and carbon dioxide move across the cell membranes by diffusion. Oxygen diffuses

from blood (high concentration) into the cell (low concentration). Carbon

dioxide diffuses from the cell (its high concentration) into the blood (its low

concentration).

27.

a)

Isotonic solutions: ideally what a cell should

be bathed in. the solute concentration inside the cell is the same as outside

of the cell. The water movement into the cell is balanced by the water

movements out of the cell.

b)

Hypotonic solutions: solutions in which the

concentration of solutes outside the cell is lower than that found in the cell.

The water molecules move into the cell. Some animal cells may burst if too much

water diffuses.

c)

Hypertonic solutions: solutions in which the

concentration of solutes outside of the cell is greater than that found inside

the cell. The water is drawn outside of the cell.

28.

*project*

29.

*reading*

1.

Page 46

#19, 21, 23, 24 and Page 48 #6, 7, 8, 10

19. The cell membrane is a bi-lipid fluid

mosaic structure that controls the chemical environment of the cell where the

cell wall is composed of cellulose and protects and provides shape to the cell.

The cell membrane is also selectively permeable. The cell wall is only found in

plant cell but the cell membrane is found in both plant and animal cells.

21. Three factors that alter diffusion rates

are pressure, temperature, and concentration.

23. Facilitated diffusion differs from

diffusion and osmosis because it uses the cell membrane proteins to form

channels. It is faster than diffusion.

24. Fertilizer is taken up by plants the same

way as water, via the root system. The fertilizer, which is the solute, creates

a hypertonic solution around the cell which draws water from the grass through

osmosis. As the plant cell loses water, it loses its Turgor pressure. Due to

the lack of Turgor pressure, the grass wilts.

6. The incredible number of mitochondria is

bees wings may explain why bees can fly. The mitochondria are the powerhouses

of the cell and are where energy is produced. If enough energy is produced it

is able to beat fast enough to lift the bee’s body off the ground.

7. (Don’t think it’s necessary – requires

digestive system knowledge)

Alycia’s answer – stomach cells have a large

number of ribosomes and Golgi apparatus because the Golgi apparatus stocks and

packages protein that would receive from our food and the ribosomes synthesize

the proteins to make them useful for our bodies

8. Steroid hormones are fat soluble so they can

easily pass through the lipid layer of the cell membrane. Lipid = fat

10. The runner’s red blood cells had burst because the

cells became hypotonic solutions. The water was rushing into the cells by

diffusion and when too much entered too quickly the cells burst since animal

cells don’t have cell walls. (Sugars and salts would have helped balance the

solution).

#7-12

#1-5

#13-21

#22-29

#30