Key Words

Question 1

Active Transport

Answer 1

• low - high concentration
• it requires metabollic energy (ATP)

Question 2

Bilayer

Answer 2

• membrane - consists of two layers of phospholipids

Question 3

Carrier Protein

Answer 3

• Spans the phospholipid bilayer- binds to ions or molecules
  CHange shape in order to move these molecules across membrane

Question 4

Cell membrane

Answer 4

• selectively permeable membrane around cell - control entry and exit of materials

Question 5

Cholesterol

Answer 5

• lipid
• important component of cell membrane - adds strength
• excess in blood leads to atheroma

Question 6

Fluid mosaic model

Answer 6

• arrangement of various molecules of cell surface membranes
• fluid because individual phospholipid molecules can move relative to one another
• mosaic as the proteins vary in shape, size, and patterns

Question 7

Glycolipid

Answer 7

Carbohydrate covalently bonded to a lipid
* act as recognition site
* help maintain stability of membrane and help cells attach to one another

Question 8

Glycoprotein

Answer 8

• carbohydrate chain attached to a protein
• Act as recognition sites
• Help cells attach to each other and recognise one another

Question 9

Partially permeable

Answer 9

• (semi-permeable)
• allows water and other small molecules
  (nothing large like starch)

Question 10

Permeability

Answer 10

• how permeable a substance is depends on size, polarity and charge of molecule
• if its small, non-polar and fat soluble = very permeable and can pass through cell membrane

Question 11

Phospholipid

Answer 11

• Triglyceride - 1 fatty acid replaced with a phosphate molecule
• important in structure and functioning of a plasma membrane

Question 12

Plasma membrane

Answer 12

• membranes consisting of a phospholipid bilayer found around and w/in all cells
• the cell-surface membrane is the plasma membrane that surrounds cells

Question 13

Protein channel

Answer 13

• Protein spanning the phospholipid bilayer - form water filled tubes to allow water - soluble ions to diffuse across the membrane

Question 14

Phospholipid bilayer

Answer 14

• barrier to dissolve substances
• centre is hydrophobic - doesn’t let water-soluble molecules (ions+polar substances)
• allows small non-polar molecules (CO2) to diffuse through

Question 15

Intrinsic Proteins

what are they?

also known as?

Answer 15

• intergral proteins - embedded in phospholipid layer may/may not extend through both layers
• Channel + carrier proteins allow large, polar molecules and ions to pass through the membrane

Question 16

attached to the bilipid layer

Peripheral proteins

Answer 16

• act as receptords + allow the cell to detect chemicals released from othercells - so they can respond
• inner or outer surface of phospholipid bilayer

Question 17

attached to the bilipid layer

Glycoproteins

Answer 17

• proteins with carbs attached

Question 18

attached to the bilipid layer

Glycolipids

Answer 18

• lipids with carbs attached

Question 19

Cholesterol

where does it bind to + function?

Answer 19

• binds to phospholipid tails - make them pack together more closely =stability

Question 20

Countercurrent flow

Answer 20

• flow of water over lamellae and flow of blood in them are in opposite directions
• keeps diffusion gradient to be maintained across the gill lamellae

Question 21

Gill

where

Answer 21

• in body of fish, behind the head

Question 22

gill filaments

Answer 22

• make up gills of a fish - stacked in a pile

Question 23

Gill lamellae

Answer 23

• right angle to gill filaments - increase S.A of gills

Question 24

Spiracle

Answer 24

• Tiny pores - allows gases to enter and leave tracheae (+water vapor to leave aswell)
• opened and closed by a valve

Question 25

Tracheae

Answer 25

• large internal network of tubes in insects - w/ supported rings to prevent them from collapsing

Question 26

Tracheoles

Answer 26

• These tubes extend from tracheae and extend thoughout all of the body tissues of the insect - allows atmospheric air tobe b rought directly to respiring tissues

Question 27

somatic cell

Answer 27

or vegetal cell, is any biological cell forming the body of a multicellular organism other than a gamete, germ cell, gametocyte or undifferentiated stem cell. Somatic cells compose the body of an organism and divide through mitosis

Question 28

germ plasm

Answer 28

Germplasm is the genetic material of an individual that may be transmitted, sexually or somatically, from one generation to another

Question 29

Magnification

Answer 29

how much bigger compared to original

Question 30

Resolution

Answer 30

how far apart two points can be before theyre seen as one