Chapter 1 - cell structure and function

Question 1

homeostasis

potential energy

Answer 1

the body’s ability to maintain a stable and constant internal condition
energy stored within a physical system

Question 2

pathogen

Answer 2

disease-causing agent; usually a bacteria, virus or fungi

Question 3

• enzyme

* co-factor

Answer 3

• substance that helps catalyze chemical reactions
• A co-factor is a chemical compound that is required for certain enzymes — called conjugated enzymes — to become active e.g. vitamins & minerals serve a so-factors

Question 4

macronutrient
micronutrient
phytochemical

Answer 4

nutrient the body requires in large amounts (i.e. fat, carbohydrates, protein)
nutrient the body requires in very small amounts (i.e. vitamins and minerals)
chemical substance obtained from plants that is biologically active but non-nutritive

Question 5

epithelial tissue

Answer 5

tissue composed of cellular layers that protect outer surfaces of the human body such as skin, mucosa and intestinal lining

Question 6

muscle tissue

Answer 6

tissues consisting of bundles of cells that contract when stimulated

Question 7

• nucleus
• gene
• chromosomes

Answer 7

• organelle where genetic material is housed
• a particular sequence in DNA or RNA that controls the expression of a protein, and by extension influences the characteristics of an organism
• organised structure of DNA, found within cells, that contains the genes of an organism

Question 8

genetic polymorphism

Answer 8

variation in the form of one or a sequence of genes

Question 9

diurnal

Answer 9

daily cycle e.g. of hormone release

Question 10

lipid

Answer 10

organic substance that is insoluble in water; provides structure, storage and messenger functions in the body

Question 11

cholesterol

Answer 11

Cholesterol is an essential part of our bodies; it makes up part of all cell membranes and helps produce several hormones. Some cholesterol comes from our diet, but most is made in the liver from saturated fats.

Question 12

phospholipids

Answer 12

a type of lipid with a hydrophilic phosphate group “head” and hydrophobic fatty acid “tail” that forms cell membranes

Question 13

hydrophilic

hydrophobic

Answer 13

• strong affinity for water

* lack of affinity for water

Question 14

mitochondria

cristae

Answer 14

• organelles that supply the cells’ energy/ATP

* the inner membrane is folded into cristae

Question 15

oxidize

Answer 15

to combine with oxygen

Question 16

adenosine triphosphate (ATP)

Answer 16

adenosine molecule with 3 phosphate groups that supplies energy for the cell

Question 17

mitochondrial density

mitochondrial quality

Answer 17

• quantity of mitochondria per unit volume

* specific attributes of mitochondria

Question 18

reactive oxygen species (ROS)

Answer 18

various substances produced as a byproduct of metabolism that are highly reactive due to the unpaired electron shell

Question 19

free radical

Answer 19

free radicals are atoms or molecules with an unpaired electron and are produced all the time in our bodies as a result of normal metabolism and energy production. In large numbers they have the potential to wreak havoc on the body but some help to fight disease, kill bacteria and heal cuts. the problems arise when too many are produced and they cannot be controlled by the body’s defence system.

Question 20

• transcription

* translation

Answer 20

• construction of mRNA from a DNA molecule

* forming a protein molecule based on the information contained in the mRNA

Question 21

endoplasmic reticulum

Answer 21

is a circulatory network located inside the cytoplasm. Rough ER (with ribosomes) is the site of protein synthesis after receiving message from DNA

Question 22

golgi apparatus

Answer 22

Cytoplasmic organelle necessary for the modification and transport of proteins. The golgi apparatus contains cistern (like holding tanks) stacked on one another. they act like chaperones, engulfing the proteins and transporting them to the cell membranes.

Question 23

glycoproteins

Answer 23

protein that contains a carbohydrate group, involved in membrane integrity

Question 24

• lysosome

* peroxisome

Answer 24

• enzyme containing vesicles - cellular garbage disposal!

* cytoplasmic organelle with enzymes that help with the breakdown of fatty acids and other macromolecules

Question 25

1. receptor-ligand binding complex
2. signal transduction
3. second messenger

Answer 25

1. A complex formed when a chemical and receptor in the cell membrane bind together
2. conversion of one signal to another by a cell
3. substance that mediates intracellular activity.

Question 26

transport protein

Answer 26

protein that moves compounds across a membrane

Question 27

1. facilitated diffusion

2. active transport

Answer 27

1. transport that requires a carrier molecule; occurs when diffusion on it’s own is not possible
2. movement of particles from an area of low concentration to an area of high concentration; requires energy and enzymes

Question 28

1. substrate

2. co-enzyme

Answer 28

1. substance acted upon by an enzyme
2. non-protein compound that operate alongside enzymes - composed wholly or partly of vitamins. they are necessary to assist in the enzyme catalysed reactions

Question 29

1. lock & key model

2. induced fit model

Answer 29

1. model that explains enzyme specificity

2. model that suggests enzymes are rather flexible structures