Cells

Question 1

What makes prokaryotic cells different from eukaryotic ?

Answer 1

Prokaryotic cells :
- Are much smaller
- Don’t have a nucleus
- Don’t have membrane bound organelles

Question 2

What is the structure and function of the Cell Membrane ?

Answer 2

Phospholipids (acts as a barrier)
Proteins (Used for movement of non lipid soluble molecules via diffusion/transport)
Cholesterol, glycolipids, carbs (aids strength)

Controls the movement of things in and out of the cell

Question 3

What is the structure and function of the Nucleus ?

Answer 3

Nucleolus (makes ribosomes)
Chromatin (holds DNA)
Nuclear envelope (seperates nucleus from cytoplasm)
Nuclear pore (gap in nuclear envelope)

Stores DNA
Carries out Mitosis
Coordinates activity

Question 4

What is the structure and function of the Mitochondria ?

Answer 4

Cristae (fold in membrane)
Matrix (liquid between membranes)
Ribosomes (protein synthesis)
ATP synthase particles (ATP production)

Provides energy to the cell

Question 5

What is the structure and function of the Ribosome ?

Answer 5

mRNA subunits (protein synthesis)
proteins (products of protein synthesis)

Produces proteins by protein synthesis

Question 6

What is the structure and function of the Golgi Apparatus ?

Answer 6

Cisternae (modifies and packages proteins and lipids by adding carbs)
Vesicles (transports products out of the cell)

Modifies proteins and lipids

Question 7

What is the structure and function of Lysosomes ?

Answer 7

Hydrolytic enzymes (hydrolyses dead pathogens and cells)
Transport proteins (exocytosis)

Removes ‘waste’ of the cell

Question 8

What is the function of the Smooth Endoplasmic Reticulum ?

Answer 8

Stores lipids and carbs

Question 9

What is the function of the Rough Endoplasmic Reticulum ?

Answer 9

Site of protein synthesis

Question 10

What organelles does a plant cell have that an animal cell doesn’t ?

Answer 10

• Cell wall
• Vacuole
• Chloroplast

Question 11

What is the structure and function of a chloroplast ?

Answer 11

Stroma (chloroplast ‘cytoplasm’)
Ribosomes (Protein source)
Lamella and Granum (Site for photosynthesis)
Starch an lipid drops (stores energy)

Site for photosynthesis

Question 12

What is the structure and function of the Cell Wall ?

Answer 12

Cellulose microfibrils of B glucose (strength)
Plasma membrane (additional strength)

Provide structure and strength to the cell

Question 13

What is the structure and function of the Vacuole ?

Answer 13

Tonoplast (membrane, provides support)
Cell sap (stores sugars and amino acids)
Central Vacuole (may stain the plant a colour, attract pollinators)

Contains cell sap

Question 14

What organelles do Prokaryotic Cells have ?

Answer 14

Cell wall
Cytoplasm
Nucleoid
Plasmid
Ribosome
Plasma Membrane
Mesosome
Flagella
Pili

Question 15

What is the prokaryotic Cell Wall made of ?

Answer 15

Murein

Question 16

What is the structure and function of a mesosome in the prokaryotic cell ?

Answer 16

Fold in the plasma membrane (Larger surface area for respiration)

Question 17

What is the structure and function of a plasmid in the prokaryotic cell ?

Answer 17

Tiny loop of DNA (stores DNA)

Question 18

What is the use of the flagella in a prokaryotic cell ?

Answer 18

A ‘tail’ (easier movement)

Question 19

What is the use of the pili in a prokaryotic cell ?

Answer 19

Sexual Reproduction

Question 20

What is the Nucleoid in a prokaryotic cell ?

Answer 20

Loop of DNA (storage of DNA without a nucleus)

Question 21

What is the equation for magnification ?

Answer 21

magnification = (image size) / (actual size)

Question 22

What is an optical microscope ?

Answer 22

A microscope that uses light to magnify a sample

Question 23

What is a transmission electron microscope ?

Answer 23

sample stained and electrons pass through it and produce a 2D image

Question 24

What is a scanning electron microscope ?

Answer 24

beam of electrons scattered and produce a 3D image

Question 25

What are 3 main differences between optical and electron microscope ?

Answer 25

- optical can view living sample, electrons have to be due (due to vacuum conditions) - optical can produce images in colour, electrons in black/white - optical generally have a lower magnification

Question 26

How is a temporary mount made ?

Answer 26

Put a thin slice of the stained sample onto a glass slide and cover it with a cover slip

Question 27

What are the 3 rules for biological drawings ?

Answer 27

- draw in pencil - include magnification - add uncrossed labels

Question 28

What is cell fractionation ?

Answer 28

he process where cells are broken down into separate organelles to be studied

Question 29

What is the solution used in ultracentrifugation ?

Answer 29

Homogenate solution.

Question 30

What organelles come out first during ultracentrifugation ?

Answer 30

Heavier (nucleus, mitochondria, chloroplast)

Question 31

What do channel proteins move ?

Answer 31

ions

Question 32

What do carrier proteins move ?

Answer 32

Biological molecules (glucose, amino acids etc.)

Question 33

What is simple diffusion ?

Answer 33

The passive movement of non-polar molecules down a concentration gradient

Question 34

What is facilitated diffusion ?

Answer 34

Passive diffusion of polar molecules with the aid of a protein

Question 35

What is osmosis ?

Answer 35

Passive movement of water down a water potential gradient across a partially permeable membrane ?

Question 36

What is water potential ?

Answer 36

The chance of water bouncing off the membrane

Question 37

What does hypotonic mean ?

Answer 37

Higher water potential -> Water moves in

Question 38

What does isotonic mean ?

Answer 38

Same water potential -> no water movement

Question 39

What does hypertonic mean ?

Answer 39

Lower water potential -> Water moves out

Question 40

What is active transport ?

Answer 40

Movement of molecules against a concentration gradient using a phosphate from ATP -> phosphate changes protein binding site and molecule can move through membrane

Question 41

What is co-transport ?

Answer 41

Specialised protein actively moves 2 molecules with energy 1 up and 1 down

Question 42

How does active transport in the small intestine happen ?

Answer 42

1 : active transport of sodium out and potassium in 2 : lower sodium inside -> concentration gradient 3 : sodium and glucose move in by facilitated diffusion 4 : glucose diffuses into capillary via facilitated diffusion

Question 43

What are the names of the mitosis stages ?

Answer 43

Interphase (not mitosis) Prophase Metaphase Anaphase Telophase Cytokinesis (not mitosis)

Question 44

What happens during Interphase ?

Answer 44

Cell grows + replicates organelles Replicates DNA Cell grows until all organelles replicated

Question 45

What happens during Prophase ?

Answer 45

Chromosomes condense and become joined by a centromere Spindle fibres Nuclear envelope breaks down

Question 46

What happens during Metaphase ?

Answer 46

Nuclear envelope fully disappears Chromosomes line up at centre of cell Spindle fibres attach to centromeres

Question 47

What happens during Anaphase ?

Answer 47

Spindle fibres contract and pull chromosomes to opposite sides of cell (requires ATP)

Question 48

What happens during Telophase ?

Answer 48

Spindle fibres disintegrate Chromosomes reach poles and uncoil Nucleus reforms

Question 49

What is Cytokinesis ?

Answer 49

Cytoplasm splitting to 2 genetically identical cells

Question 50

How to find the mitotic index ?

Answer 50

Ratio of cells undergoing mitosis : total number of cells

Question 51

What is cancer ?

Answer 51

Uncontrolled cell division due to mutation in the DNA