Chapter 1: Life processes

Question 1

excrete

Answer 1

get rid of toxic waste products

Question 2

respond to stimuli

Answer 2

sensitive to changes in their surroundings

Question 3

control

Answer 3

internal conditions

Question 4

cytoplasm

Answer 4

living materian that makes up a cell

Question 5

structures of these

Answer 5

organelles

Question 6

nucleus

Answer 6

controls activities of cells

contains chromosomes which carry genes

Question 7

genes

Answer 7

control the activities in the cell by determining which protiens the cell can make

Question 8

Enzymes

Answer 8

control chemical reactions that go on in the cytoplasm

Question 9

cell surface membrane

Answer 9

not a complete barrier

selectively permiable

controls what substances go in + out

Question 10

metabolic reactors

Answer 10

chemical reactors taking place in a cell

Question 11

mitochondria

Answer 11

carry out some reactions of respiration

Most energy from respiration is released in mitochondria

Question 12

cell wall

Answer 12

non living

made out of cellulos

keeps its shape

freely permiable

Question 13

how do plant cells get support

Answer 13

plant cells absorb water, producing internal pressure which pulses against other cells of the plant

Question 14

vacuole

Answer 14

permanent feature

filled with cell sap - dissolved sugars, mineral ions + other solutes

Question 15

chloroplasts

Answer 15

absorb light energy to make food in photosynthesis

contain chlorophyll which makes them green

Question 16

Enzymes (protiens)

Answer 16

biological catylists

Question 17

Catalyst

Answer 17

speeds up a reaction without being used up itself

nucleus contains genes, which control production of enzymes which catalyse reactions in the cytoplasm

Question 18

Why enzymes are needed

Answer 18

temperatures in organisms are low, without catalysts most reactions would be too slow for life to go on

Question 19

substrate

Answer 19

the molecule an enzyme acts on

Question 20

Each enzyme has a small area on its surface

Answer 20

active site

Question 21

enzyme (steps)

Answer 21

substrate attaches to the active sight

reaction takes place, then products are formed

Question 22

What happens to energy when substrate joins with active site

Answer 22

Lowers the energy needed for reaction to start, allowing products to be formed more easily

Question 23

factors affecting enzymes

Answer 23

pH of surroundings

Concentration of enzyme or substrate

temperature

Question 24

optimum temperature

Answer 24

enzymes working at their best

e.g 37 degrees C in a human

Question 25

why does higher temperature increase reaction?

Answer 25

goves molecules more energy so they collide more often

Question 26

What happens at high temperature with enzymes

Answer 26

denature- enzymes are made out of protiens protiens are broken down by heat 40*C cupwards destroys the enzyme

Question 27

What happens to enzymes in extremes of pH

Answer 27

affects structure of enzyme molecules and changes the shape of its active sight so substrate will not fit in that well

Question 28

Optimum pH

Answer 28

pH at enzymes work best with

Question 29

cell respiration

Answer 29

breaking down of food molecules to release the stored chemical energy

Question 30

where does respiration happen

Answer 30

in all cells of our body

Question 31

What is oxygen used to do in respiration?

Answer 31

oxidise foods main food oxidised is glucose

Question 32

What does glucose contain

Answer 32

stored chemical energy that can be converted into other forms that the cells can use

Question 33

Chemical energy is used for

Answer 33

contraction of muscles active transport of molecules + ions building large molecules such as protiens cell division

Question 34

Aerobic (later steps)

Answer 34

happen in the mitochondria

Question 35

anaerobic respiration

Answer 35

glucose is not completely broken down less energy is released

Question 36

Advantages of anaerobic respiration

Answer 36

it can occure when oxygen is in short supply e.g. yeast or muscle cells

Question 37

anaerobic equation for yeat

Answer 37

glucose -> ethanol + carbon dioxide

Question 38

anaerobic equation for muscle cells

Answer 38

glucose -> lactic acid

Question 39

lactic acid

Answer 39

substance glucose is broken down into

Question 40

Why does person rest after anaerobic repiration

Answer 40

to oxidise the lactic acid FULLY

Question 41

oxygen debt

Answer 41

volume of oxygen needed to COMPLETELY oxidise the lactic acid during anaerobic respiration

Question 42

diffusion

Answer 42

happens when a substance is more concentrated in one place than the other cell membrane is permiable to e.g. CO2 so there is a NET movement

Question 43

diffusion of oxygen

Answer 43

opposite of CO2 Respiration uses O2 so net movement of O2 into cell by diffusion

Question 44

Why does diffusion happen

Answer 44

Kinetic energy of the particles

Question 45

Active transport

Answer 45

goes against the concentration gradient the cell uses energy from respiration to take up the particles "pumping" it

Question 46

What are the "pumps" made of?

Answer 46

large protien molecules located in the cell membrane

Question 47

active transport in humans

Answer 47

small intestine-> some glucose is absorbed into the cells lining the intestine by active transport

Question 48

active transport in plants

Answer 48

roots

Question 49

osmosis

Answer 49

water moving accross cell membrane Partially permiable

Question 50

when does osmosis happen?

Answer 50

when the total concetration of all substances inside and out is different water will move across the membrane from the more dilute soloution to the more concentrated one (obeys law of diffusion)

Question 51

rate of diffusion increased by

Answer 51

steep concentration gradient high temp large surface area

Question 52

diffusion examples

Answer 52

alvioli villi (of the mall intestine) spingy mesophyll

Question 53

zygote

Answer 53

multicelular organism beginning life as an egg

Question 54

tissues

Answer 54

cells with familiar functions

Question 55

organ

Answer 55

collection of several tissues carrying out a particular function

Question 56

organ system

Answer 56

jobs carried out by several different organs working togethor

Question 57

main systems in human body

Answer 57

digestive respiratory circulatory excretory nervous endocrine reproductive

Question 58

eukaryotes

Answer 58

complex: animal + plant cells

Question 59

prokaryote

Answer 59

single celled organism - prokrayotic cell