cell division

Question 1

Cell Membrane

Answer 1

Soft and flexible
Separates inner and external environments
Controls the flows of materials in and out of the cell

Question 2

Centrioles

Answer 2

ONLY FOUND IN ANIMAL CELL
Controls movement of chromosomes during cell division

Question 3

Cytoplasm

Answer 3

A jelly like substance full of proteins and nutrients that fill the cell
The other organelles are suspended in the cytoplasm

Question 4

Cytoskeleton

Answer 4

Strand of proteins that gives the cell its shape and helps it move.
Acts as tracks on which vacuoles and organelles move.

Question 5

Endoplasmic Reticulum

Answer 5

Transports materials made in cells
Rough E.R: covered in ribosomes and associated with making proteins.
Smooth E.R: associated with production of fats and oils and does not have ribosomes on it.

Question 6

Golgi Apparatus

Answer 6

Modifies, sorts and packages proteins for transport within or out of the cell

Question 7

Lyosomes

Answer 7

ONLY FOUND IN ANIMAL CELLS
Contains enzymes to digest invading bacteria or damaged organelles

Question 8

Mitochondria

Answer 8

Make energy from nutrients
Make all energy for the cells
Mitochondrion = Singular
Mitochondria = Plural

Question 9

Nucleus

Answer 9

Contains the cell’s DNA
Controls cell activity : growth & reproduction
Contains the Nucleolus which makes ribosomes.

Question 10

Ribosomes

Answer 10

Make proteins
Found in the cytoplasm and on the Rough E.R

Question 11

Vacuoles

Answer 11

Holds water and other materials
Used to move small molecules around the cell
Plants cells have one big Vacuole
Animals cells have small many Vacuole

Question 12

Vesicles

Answer 12

Used to move materials into and out of the cell

Question 13

Cell Wall

Answer 13

ONLY FOUND IN PLANTS
A hard wall outside of the cell membrane
Protects the cell and gives it shape and strength

Question 14

Chloroplasts

Answer 14

ONLY FOUND IN PLANT CELLS
Where photosynthesis happens (Makes sugar from CO2, H2O and Sunlight)

Question 15

Which are only found in Animal Cells?

Answer 15

Lyosomes
Centrioles

Question 16

Which are only found in Plant Cells?

Answer 16

Cell Wall
Chloroplasts

Question 17

Chromatin/
chromosomes

Answer 17

Chromatin is the uncondensed form of DNA and proteins, while chromosomes are the condensed, visible structures formed from chromatin during cell division
Chromatin: Regulates gene expression, DNA packaging.
Chromosomes: Carry genetic information, ensure accurate transmission during cell division.

Question 18

Describe the differences between plant and animal cells?

Answer 18

Cell Wall:

Plant Cells: Have a cell wall made of cellulose.
Animal Cells: Lack a cell wall.
Chloroplasts:
Plant Cells: Contain chloroplasts for photosynthesis.
Animal Cells: Lack chloroplasts.
Vacuoles:
Plant Cells: Have one large central vacuole.
Animal Cells: Have smaller or multiple vacuoles.
Shape:
Plant Cells: Often fixed rectangular or square shape.
Animal Cells: Varied shapes, often roundish.

Question 19

Explain the structure of phospholipids

Answer 19

Phospholipids have a hydrophilic (water-attracting) head and hydrophobic (water-repelling) tail.
In water, phospholipids spontaneously arrange themselves into a double layer with the heads facing outward towards the watery environment and the tails tucked inward, away from water.

Question 20

Fluidity/ Selectively permeability

Answer 20

The membrane is constantly in motion, with phospholipids moving laterally within the bilayer.
This fluidity allows for small molecules like oxygen and carbon dioxide to pass through the membrane easily.
The membrane is selectively permeable, meaning it allows some molecules to pass through while blocking others.
Small molecules and certain proteins help transport materials across the membrane

Question 21

What are some roles of a membrane in a cell

Answer 21

• Isolation of enzymes
• Transportation of materials/substances
• Make proteins and lipids
• Cell communication

Question 22

Why are cells quite small? OR Why are we multicellular?

Answer 22

The size of a cell is limited by its ability to obtain the materials needed for survival and its ability to get rid of waste.
The cell’s VOLUME determines the amount of materials it needs, but its SURFACE AREA determines how much it can obtain, since all these materials must pass through the cell membrane.

Question 23

Particle Theory

Answer 23

All particles move randomly due to their kinetic energy (which is related to their temperature!!)
If the particles are in a FLUID, this movement will cause them to naturally get farther apart and spread out within their available volume.
This behaviour is known as DIFFUSION

Question 24

Diffusion

Answer 24

the net movement of materials from an area of high concentration to an area of low concentration.
concentration is calculated by the number of particles of a substance present in a particular volume.
Equilibrium: Diffused evenly

Question 25

Factors affecting the speed of Diffusion

Answer 25

Temperature Distance Travelled Mass of the particle Density of the medium Concentration Gradient

Question 26

Diffusion through Membrane:

Answer 26

A molecule can diffuse through the membrane if it is small enough to fit between the spaces in between phospholipids and proteins. It is non polar so it is able to go between fatty acids tails. ONLY CO2 and O2 can do this!

Question 27

Passive Transport

Answer 27

- No energy is required - Uses natural movement of molecules of particles to move them in and out of cells *Diffusion is the most simplest form of passive transport

Question 28

Facilitated Transport

Answer 28

- Uses membrane proteins to help move materials a) Osmosis - Using the movement of water such as aquaporins. Because water is polar it can not use simple diffusion

Question 29

Facilitated Diffusion

Answer 29

Uses transport proteins in the membrane to move a variety of molecules in and out of cells. Each protein can move ONLY its target molecule. (specific) Each molecule must move from high to low concentration. The cell does not use any additional energy to do this. i) Channel Proteins - create a “tunnel” for molecules to travel through. ii) Carrier Proteins - change shape

Question 30

Active Transport

Answer 30

- Uses energy to move materials across the membrane - Used when particle is too large to move or theres too many particles to move. Or when particles are being moved against their concentration gradient (low conc. to high)

Question 31

Primary and Secondary Active Transport

Answer 31

Primary - the transport protein itself uses the energy released by the ATP molecule to transport the particle. Secondary - the transport protein uses a type of potential (stored) energy to transport the particle. This potential energy is in the form of a concentration gradient of some other particle Example: Sodium Potassium Pump

Question 32

Sodium Potassium Pump

Answer 32

The sodium-potassium pump works like a tiny pump in our cells. It moves sodium (Na⁺) and potassium (K⁺) ions across the cell membrane, against their concentration gradients, using energy from ATP 1. The pump binds three sodium ions inside the cell. 2. ATP provides energy to change the shape of the pump, moving the sodium ions outside the cell. 3. The pump then binds two potassium ions from outside the cell. 4. This triggers another shape change, releasing the potassium ions inside the cell. 5. The pump is now ready to start the cycle again.

Question 33

Antiporters vs Symporters

Answer 33

Antiporters: Antiporters are proteins that move two different types of molecules across a cell membrane in opposite directions. where one molecule goes in while another comes out. For example, the sodium-potassium pump is an antiporter that moves sodium ions out of the cell while bringing potassium ions into the cell. Symporters: proteins that move two different types of molecules across a cell membrane in the same direction. where both molecules move together in one direction. For example, the sodium-glucose symporter moves both sodium ions and glucose molecules into the cell together.

Question 34

Bulk Transport/Cytosis

Answer 34

type of active transport that uses the ability of the cell membrane to “pinch off” to create vesicles, or to fuse vesicles with the membrane. (Does require energy)

Question 35

Types of Endocytosis:

Answer 35

- Bringing Material into cell (Endo = Enter) 1. Pinocytosis - This is like the cell drinking. It takes in fluids along with any dissolved molecules by forming small vesicles 2. Receptor Mediated Endocytosis - uses recognition proteins on the cell surface to select specific molecules to be brought into the cell. 3. Phagocytosis - This is like the cell eating something. It engulfs large particles, such as food or bacteria, and forms a vesicle to bring them inside. used by amoeba and other protists to bring in food particles.

Question 36

Exocytosis

Answer 36

- Exiting the cell (Exo = Exit) - The process of exocytosis allows the cell to secrete materials into its surroundings. -These materials can include wastes, hormones, enzymes, or other substances, like the waxy coating on leaves. -Often it is the vesicles packaged by the Golgi body which undergo exocytosis.

Question 37

Types of Concentration

Answer 37

1. Higher concentration: Hypertonic 2. Lower concentration: Hypotonic 3. Equal Concentration: Isotonic

Question 38

Channel Proteins

Answer 38

- Proteins that can pass through water because their channels are hydrophilic Aquaporins

Question 39

Vesicular Transport

Answer 39

When vesicles help to move molecules into a cell

Question 40

Plasmodesta

Answer 40

Plants only Function: Channels between plant cells for sharing nutrients and communication.

Question 41

Gap junctions

Answer 41

Animals Function: Channels between animal cells for communication.

Question 42

Tight Junctions

Answer 42

Animals Function: Seals between animal cells to prevent leakage of fluids.

Question 43

Desmosomes

Answer 43

Function: Spot welds between animal cells for strength and stability.

Question 44

Cell connections.....

Answer 44

These connections help cells in plants and animals communicate, stay connected, and maintain their structure.