Cells

Question 1

What are the 3 main elements that structure a cell?

Answer 1

1. Plasma membrane
2. Cytoplasm
3. Nucleus

Question 2

What is the plasma membrane made of?

Answer 2

• liquid bilayer
• contains phospholipids, cholestoral and glycolipids
• Has integral and peripheral proteins

Question 3

What does the plasma membrane do?

Answer 3

• acts as barrier, controlling the flow of substances into cell
• contributes to interceullar signalling

Question 4

What are the main 2 elements of cytoplasm?

Answer 4

• cytosol
• organelles

Question 5

What makes up cytosol?

Answer 5

• intracellular fluids
• dissolved solutes
• suspended particles (proteins etc)

Question 6

What are organelles?

Answer 6

Specialised cell structures

Question 7

Name 4 organelles

Answer 7

• centrosome
• cillia and flagella
• ribosomes
• endoplasmic retriculum
• golgi complex
• lysosomes
• peroxisomes
• proteasomes
• mitrochondria

Question 8

What are centrosomes?

Answer 8

• pair of centrioles in a structure called pericentricolar matrix
• near nucleus

Question 9

What do centrosomes do?

Answer 9

• organise mitotic spindle microtuble formation

Question 10

What are cillia and flagella?

Answer 10

• ‘hairs’ on cells that allow them to move
• mostly on microtubles

Question 11

what is the difference between cillia and flagella?

Answer 11

• cillia are short and hair-like (fallopian tubes)
• flagella are long and wavy (sperm)

Question 12

What are ribosomes?

Answer 12

• combination of large and small sub units
• produce proteins around messenger RNA

Question 13

What are ERs?

Answer 13

• large folded membrane connecting cytoplasm and nuclear envelope

Question 14

What are the 2 tyes of ERs and their purposes?

Answer 14

• smooth: synthesises fatty acids, steroids, drugs
• rough: ribosome home, proteins made

Question 15

What is the golgi complex?

Answer 15

• it is where proteins from ER go to be processed
• it has secretatory vesicles to secrete processed proteins

Question 16

What are lysosomes?

Answer 16

Digestive enzymes within a membrane

Question 17

What do lysosomes do?

Answer 17

• autophagy (recycle)
• autolysis (destroy)

Question 18

How do peroxisomes work?

Answer 18

• they contain oxidases and catalase
• oxidases interact with hydrogen to make hydrogen peroxide
• hydrogen peroxide oxides toxic substances in liver
• excess is degraded by catalase

Question 19

What are proteasomes?

Answer 19

• barrel shaped structures
• contain protease to disolve uneeded or abnormal proteins

Question 20

What is produced in the mitrochondria?

Answer 20

• ATP

Question 21

What membranes are present in the mitrochondria?

Answer 21

• outer smooth
• inner folded with large surface area for ATP production

Question 22

What is the cytoskeleton?

Answer 22

cell’s skeleton

Question 23

What protein filaments make up the cytoskeleton?

Answer 23

• microfilaments
• intermediate filaments
• microtubles

Question 24

what do microfilaments do?

Answer 24

• control muscle contraction, cell division and locomotion
• high tension

Question 25

what do intermediate filaments do?

Answer 25

* they have high tensile strength * hold organelles in place

Question 26

What do the microtubles do?

Answer 26

* they're large and hollow with compressive strength * they control cell shape and organelle movement

Question 27

what is the name for the structure of the cytoskeleton?

Answer 27

dynamic tensegrity ## Footnote network of isolated components under compression within a system of continuous tension

Question 28

What is the structure of the nucleus?

Answer 28

* surrounded by nuclear envelope * contains nucleoli where ribosomes are assembled * has chromosomes that contain DNA