chapter 5 membranes

Question 1

what is the plasma membrane composed of

Answer 1

phospholipid bilayer

Question 2

What are the structure difference between an animal and plant cell

Answer 2

plant cells contain a cell wall composed of carbohydrates (cellulose), has central vacuoles and chloroplasts

animal cells have lysosomes

Question 3

in terms of cell organelles what is the function of centrosomes

Answer 3

• creates a actin filament that organizes the organelles in the cell
• during mitosis it is used to pull apart chromosomes apart to make sure chromosomes are present in all new cells

Question 4

in terms of cell organelles what is the function of the plant cell wall

Answer 4

is used as a barrier to infections, keeps the cell parts inside the cell, manages what is lead in and out of the cell

Question 5

in terms of organelles what is the function of chloroplasts

Answer 5

harness energy from the sun to produce energy that is need to break down water molecules in the hydrogen gradients for photosynthesis

Question 6

in which part of the chloroplast does photosynthesis occur

Answer 6

in the thaylakoid which is located in the thaylakoid membrane

Question 7

in term of organelles what is the function of the central vacuole

Answer 7

-provides the cell with structural support
- provides a resouvier for water (stores water)

Question 8

what is the number on trait of the central vacuole

Answer 8

will shrink or expand to fit the amount of water that is found in the cell

Question 9

what is endosymbiosis

Answer 9

when two cells that are joined together when one cell engulfs the other one but they still run as two seperate cells but rely on each other for materials for basic life

Question 10

what type of cells are involved with endosymbiosis

Answer 10

prokaryotic

Question 11

what is the endomembrane system

Answer 11

consists of membrane that works together to modify, package, and transport lipids and proteins

Question 12

what does the endomembrane system includes

Answer 12

-nuclear envelope
- lysosomes
- vesicles
- endoplasmic reticulum
- golgi apparatus
- plasma membrane

Question 13

which two organelles has an endomembrane system

Answer 13

mitocondria and chloroplasts

Question 14

in terms of cell organelles what is the functions lysosmes

Answer 14

an organelles that has digestive enzymes that breaks down larger biomolecules and worn out organelles ( breaks them down into their simpliest units)

Question 15

in terms of cell organelles what is the function of the endoplasmic reticulum

Answer 15

produce proteins or lipids needed by the cell

Question 16

in terms of cell organelles what is the function of the rough endoplasmic reticulum

Answer 16

is covered in ribosomes that read the mRNA seuences and produces protein needed by the cell

Question 17

in terms of cell organelles what is the function of the smooth endoplasmic reticulum

Answer 17

• manifactures lipids, carbhoydrates, and steroid hormones (lipids)
• detoxification of medication and poisons
• storage of Ca+ (in the muscles cells)

Question 18

where is the endplasmic reticulum located and what is the significance of this placing

Answer 18

is located on the outside membrane of the nucleus so it can instantly pickup coding from the nucleus and translate it into molecules needed by the cell

Question 19

in terms of organelles what is the function of the golgi apparatus

Answer 19

packages and ships the molecules produced by the endoplasmic reticulum by creating vesicles

Question 20

in terms of organelles what is the function of the cytoskeleton

Answer 20

• maintains shape of the cell
• holds organelles in specific positions
• allows movement of cytoplasm and vesicles within the cells
• enables cells with multicellular organisms to move

Question 21

what are the three components of the cytoskeleton

Answer 21

microfilaments
microtubules
intermediate filaments

Question 22

what is the function of microfilaments

Answer 22

• involved in movement of the whole cell or inside cell movement
• determine and stabilizes the shape of cell

Question 23

what is the function of microtubules

Answer 23

• provides framework for motor proteins to move structures within cells
• forms rigid internal skeleton for some cells

Question 24

what is an intercellular junction

Answer 24

provides direct channels of communication between cells (when cells attach to each other by plasma membrane)

Question 25

what are the intercellular junction of plants called

Answer 25

plasmodesmata

Question 26

what is plasmodesmata

Answer 26

the intercellular junction has channels containing cytoplasm that allows material (nutrients) from cell to cell

Question 27

what are the 3 different types of intercellular junctions of animals cells

Answer 27

- tight junction - desmosomes -gap junctions

Question 28

what is a tight junction in relation to intercellular junctions

Answer 28

when cells are held together by a watertight seal that prevents materials from leaking between cells

Question 29

what is a desmosome in relation to intercellular junctions

Answer 29

short proteins in the plasma membrane that acts as a weld (anchor cells together and to the proteins)

Question 30

what is gap junctions in relation to intercellular junction

Answer 30

forms channels that allow ions, nutrients, and other materials to move between cells

Question 31

what is the function of the plasma membrane

Answer 31

- defines outer boarders of cells and organelles inside and outside the cell - manages what enters or exists the cell - reciving external signals and intitating cellular responses - hold onto anchoring proteins

Question 32

what is the fluid mosaic model

Answer 32

a model of how the phospholipid bilayer is formed

Question 33

what is the most important thing to note about the fluid mosaic model

Answer 33

the top layer and bottom layer of phospholipids are not connected and can move independently of each other (phospholipids can move around the integral and peripheral protein)

Question 34

what is the role of the glycerol molecule in the phospholipid

Answer 34

attaches the phosphate group to the fatty acid chains

Question 35

in the fatty acid tail of a phospholipid, what is the structure of the two fatty acid tails

Answer 35

one fully saturated tail and one unsaturated tail (the more kinks in the structure the more fluid)

Question 36

what is found in the phospholipid bilayer

Answer 36

- charged phospholipid molecules - cholestrol molecules - different forms of protein channels - carbohydrates identifiers

Question 37

what are the two different types of proteins found in the phospholipid layer of a cell

Answer 37

- integral protein - peripheral protein

Question 38

what is an integral protein

Answer 38

a protein channel in the phospholipid membrane that runs from one side of the bilayer to the other side of the bilayer

Question 39

what is a peripheral protein

Answer 39

a protein that is known as an anchoring protein and is only connects from one side of the phospholipid membrane

Question 40

where are the carbohydrates located in the plasma membrane

Answer 40

is located on the exterior surface of the cell and is used to identify who we are based on the cells

Question 41

what is membrane fludity

Answer 41

the meaning of where a membrane need to be flexible but not completely fluid

Question 42

what are the 3 factor that affect the fuldity of a membrane

Answer 42

- phospholipid type: how tightly packed the acids are based on the structure of the two fatty acid chains - temperature : colder temps will compress molecules making the membrane more rigid - chlorestrol: the more chlorestorol the higher heat resistance a cell has

Question 43

what is transport

Answer 43

the movement of materials in and out of the cell

Question 44

what factor plays a key role in transport? And why?

Answer 44

the selectively permability of the semipermable membrane and it controls what molecules pass through the membrane

Question 45

what are the 2 different types of transport

Answer 45

- active - passive

Question 46

what is passive transport

Answer 46

a type of transport that does not require any energy and is diffusion which transport Carbon, oxygen, water, and salts (COWS) in and out of the cell until equilibrium is reached

Question 47

what is facilitated transports also known as

Answer 47

facilitated diffusion - still no energy is used

Question 48

what is facilitated transport

Answer 48

movement of substance down their concentration gradients through integeral membrane proteins

Question 49

what are carrier proteins

Answer 49

a protein channel that is specific to a certain substance and opens one end as the at a time while the other one closes (allows movement in either direction as the gradient changes)

Question 50

what is osomosis

Answer 50

the diffusion of water from a low solute concentration to a higher solute concentration

Question 51

what is tonicity

Answer 51

the level of solutes in a solution

Question 52

what are the three different types of tonicity

Answer 52

hypertonic hypotonic isotonic

Question 53

what is osmoregulation

Answer 53

the process in which the vacuole changes size and how it changes the cell of the cell (expand or shrink)

Question 54

what is active transport

Answer 54

transport that requires energy to transport molecules from a low concentration to a high concentration

Question 55

what are the two types of active transport

Answer 55

primary transport: where ATP provides energy secondary transport: where an electrochemical gradient provides the energy

Question 56

What is an electrochemical gradient

Answer 56

a movement of an ion between a charged barrier (cytoplasm contains negatively charged ions)

Question 57

What are the different types of carrier proteins

Answer 57

uniporter (one molecule one way) symporter (two different molecules in one direction) antiporter (two different molecules on two different direction)

Question 58

What is bulk transport

Answer 58

moving multiple things either in or out of the cell at a given time (more energy needed for larger loads)

Question 59

what is endocytosis

Answer 59

importing bulk transport

Question 60

what are the three types of endocytosis

Answer 60

phagocytosis pinocytosis receptor mediated endocytosis