Ch 5 Cell Function and Structure

Question 1

why are cells important

Answer 1

cells are the basic unit of all life

Question 2

who invented the telescope and microscope

Answer 2

Anton Van Leeuwenhoek is credited with inventing the telescope and microscope in the 1600s both of which lead to many discoveries

Question 3

who named cells

Answer 3

Robert Hooke used microscopes of his own design to look at cork and see many little chambers he named cells

Question 4

what are the three statements of cell theory

Answer 4

• Cell theory states:
  
  • All living things are made of cells
  • Cells are the basic units of structure and function in living things
  • All cells come from pre-existing cells

Question 5

what are the three basic parts of any cell

Answer 5

• 3 basic parts:
  
  • Cytoplasm
  • Cell membrane
  • information (in the form of DNA)

Question 6

what does the cell membrane do

Answer 6

• separates the inside of the cell from the out
• regulates entry into/out of the cell

Question 7

what makes up the cell membrane

Answer 7

• Composed of:
  
  • Lipids: a bilayer forming the basic wall
  • Proteins: allow entry through channels and pumps
  • Carbohydrates: on the outside of the wall, identify cells and materials

Question 8

what is the cell wall

Answer 8

• a structure found in plant, algae, some bacteria, etc
• Lies outside the cell membrane
• Very porous, and more rigid than the membrane

Question 9

what are the layers of the cell wall

Answer 9

• has 2-3 layers:
  
  • Pectin is a gluey substance that holds cells together
  • Cellulose is the primary wall, its fibrous and elastic so it can stretch as the cell grows
  • lignin + cellulose from the woody layer of wood, more rigid

Question 10

what organisms have a nucleus

Answer 10

• Present in most organisms (Eukaryotes)
• but some bacteria don’t have one (Prokaryotes)

Question 11

what makes up the nucleus

Answer 11

• the nuclear envelope is a dual membrane that forms the outer barrier of the nucleus. Covered in openings called nuclear pores
• the Nucleolus is a small region made of RNA and proteins that fabricates ribosome parts

Question 12

what is the purpose of the nucleus

Answer 12

the nucleus holds the genetic info of the cell. this information lets the cell function and reproduce

Question 13

what are chromosomes

Answer 13

DNA attached to proteins that forms an X shaped structure

Question 14

what is cytoplasm

Answer 14

a jelly like substance between the nucleus and cell membrane that contains the organelles and other materials

Question 15

what are organelles

Answer 15

Organelles are tiny structures that perform a specialized function in a cell

Question 16

what does the mitochondria do

Answer 16

change chemical energy from food into compounds the cell can use

Question 17

what does the chloroplast do

Answer 17

traps the energy of the sun and converts it to chemical energy

Only present in plants and other photosynthesizes

Question 18

what are ribosomes

Answer 18

made of RNA and proteins. float around or attached to various membranes. Synthesize proteins

Question 19

what is the ER

Answer 19

A complex network of sacs that transport material around the cell

the rough ER has ribosomes while the smooth ER does not

Question 20

what are the Golgi bodies

Answer 20

Special compartments in which proteins are modified before release

Question 21

what do lysosomes do

Answer 21

contain chemicals and enzymes that digest materials and old organelles in the cell

formed by Golgi

Question 22

what do vacuoles do

Answer 22

store materials like water, salt, and proteins

plants have one very large vacuole

Question 23

what are plastids

Answer 23

plant organelles that take many forms. One is chloroplast

store food and pigments

Question 24

what is the cytoskeleton

Answer 24

a variety of filaments and fibres that drive movement and support cell structure

Question 25

what are cells surrounded by

Answer 25

cells are surrounded by extra-cellular fluid that allows materials to move from cell to cell

Question 26

what is diffusion

Answer 26

• molecules move around and collide, causing them to move from the zone of highest concentration to the zone of lower concentration
• Diffusion is the process by which molecules of a substance move from areas of high concentration to area of low concentration

Question 27

how does diffusion act in regards to a membrane

Answer 27

• when two areas of equal concentration are divided by a membrane, particles diffuse to the lower [] side until equilibrium is reached
• at equilibrium particles still move back and forth, but in equal measure
• a membrane needs to be permeable for particles to traverse its barrier

Question 28

what kind of permeability do most biological membranes have

Answer 28

most biological membranes are selectively permeable, letting some particles across but not all

Question 29

what is osmosis

Answer 29

• Osmosis is the diffusion of water
• water passes across membranes very easily
• water will experience osmosis to dilute more concentrated solutions

Question 30

how can osmosis impact cells

Answer 30

• too much or too little water in a cell is bade for it
• some cells will use special vacuoles to pump water out of them

Question 31

what is facilitated diffusion

Answer 31

• a carrier protein takes substances across a cell membrane
• still operates via diffusions
• requires no energy and is considered passive transport

Question 32

what is active transport

Answer 32

transport across a cell membrane that operates from the area of low concentration towards high concentration requires energy

Question 33

what type of active transport are proteins involved in

Answer 33

protein pump can form certain particles into the cell

Question 34

what is endocytosis

Answer 34

endocytosis is a process where a large quantity of material is brought into a cell. in endocytosis the membrane folds around the material making a pocket that goes into the cell becoming a vacuole/vesical

Question 35

what are two types of endocytosis

Answer 35

• when large particles are brought in through endocytosis it is called phagocytosis
• when many little particles or liquids are brought into the cell it is called pinocytosis

Question 36

what is the opposite of endocytosis

Answer 36

exocytosis is like the opposite of endocytosis where materials leave the cell

Question 37

how does the body achieve specialization through cells

Answer 37

cells can be uniquely specialized to a function

Question 38

how might cells be different in the pancreas

Answer 38

certain cells in the pancreas can produce digestive enzymes. they have 100x the normal quantity of protein producing organelles

Question 39

what might a light sensitive cell be like

Answer 39

contains lost of mitochondria and has disks of a pigment that react to light

Question 40

what types of cell might be found in the trachea

Answer 40

in the trachea one type of cell releases mucus while another sweeps the mucus upwards with little hairlike projections

Question 41

what are the first four levels of biological specialization

Answer 41

Cells

Tissues: a group of similar cells that perform a similar function. Generally one type of cell per tissue

Organs: a group of tissues that work together to perform a function

organ systems: a group of organs in a system that perform a function. the human body has around 10-11 organ systems.