Download Cellular Respiration

GLYCOLYSIS &
CELLULAR RESPIRATION
The process of
breaking down
“food”
molecules
OBJECTIVES: SWBAT…
  compare & contrast photosynthesis & cellular
respiration
  define glycolysis & cellular respiration, be able to
outline the general steps & molecules involved in
each, & state which in an aerobic process and which
is an anaerobic process
  define aerobic & anaerobic;
  identify that glycolysis happens in the cytoplasm &
respiration occurs in the mitochondria organelle
  identify where specifically in the mitochondria
organelle the Krebs cycle and the electron transport
chain of cellular respiration occur
  define calorie
11/28/16
Cellular Energy: Glycolysis & Respiration
2
COMPARISON OF PLANT & ANIMAL CELLS
11/28/16
Cellular Energy: Glycolysis & Respiration
3
ATP AND GLUCOSE
ATP
short term storage of
energy; breaks down to
ADP & loses energy
transfers energy very
quickly
Glucose
long term storage of
energy; can hold 90x more
energy than ATP.
takes longer to get energy
out
AEROBIC VS. ANAEROBIC
 anaerobic – any process that does not
require oxygen (occurs in the absence of oxygen)
 aerobic – any process that requires oxygen
(with air)
11/28/16
Cellular Energy: Glycolysis & Respiration
5
GLYCOLYSIS & RESPIRATION OVERVIEW
Mitochondrion Electrons carried in NADH Electrons carried in NADH and FADH2 Pyruvic acid Glucose Glycolysis Cytoplasm 11/28/16
Krebs Cycle Electron Transport Chain Mitochondrion Cellular Energy: Glycolysis & Respiration
6
GLYCOLYSIS & RESPIRATION
  organism breaks down fuel (usually glucose)
to capture energy in a usable form (ATP)
  2 processes by which organisms release
energy from glucose:
  glycolysis (glucose-breaking): ATP production by
conversion of glucose to pyruvic acid
  respiration: process involving oxygen & break
down of food molecules to release energy
  Krebs cycle (aka citric acid cycle)
  electron transport chain
11/28/16
Cellular Energy: Glycolysis & Respiration
7
GLYCOLYSIS & RESPIRATION
  glycolysis
  occurs in cytoplasm
  anaerobic process
  cellular respiration
  occurs in mitochondria
organelle
  aerobic process
11/28/16
Cellular Energy: Glycolysis & Respiration
8
COMPARISON OF PLANT & ANIMAL CELLS
11/28/16
Cellular Energy: Glycolysis & Respiration
9
GLYCOLYSIS & RESPIRATION:
BREAKING DOWN OF GLUCOSE
ATP
C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + Energy
Requirements:
  C 6 H 1 2 O 6 – organic
sugar comes from
digested foods
eaten
  6 O 2 – o x y g e n
comes from air
you breathe
11/28/16
Products:
  6CO 2 – carbon dioxide is
released by breathing out
  6H 2 O – water is released
as a waste in your urine,
sweat or breath
  Ene rgy – c he m ical AT P
energy is released
Cellular Energy: Glycolysis & Respiration
10
GLYCOLYSIS & RESPIRATION:
BREAKING DOWN OF GLUCOSE
ATP
C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + Energy
sugar
(glucose)
+
oxygen

carbon
dioxide
+
water
+
ATP
  gives off 3811 calories per gram of glucose
  calorie – amount of heat energy required to
raise temperature of 1g of water 1°C
  unit of measurement for energy found in food
11/28/16
Cellular Energy: Glycolysis & Respiration
11
GLYCOLYSIS
  glycolysis
  occurs in cytoplasm
  anaerobic process
11/28/16
Cellular Energy: Glycolysis & Respiration
12
GLYCOLYSIS: BREAKING DOWN GLUCOSE
  "splitting sugars”; produces
small amount of energy, very
quickly by breaking down glucose
(6-carbon sugar) molecules into
2 (3-carbon) pyruvate molecules
  very complex series of reactions
  every step initiated by a specific
enzyme; series of enzymes
catalyzes chemical reactions that
change glucose, 1 step at a time,
into different molecules
11/28/16
Cellular Energy: Glycolysis & Respiration
13
GLYCOLYSIS: BREAKING DOWN GLUCOSE
GLYCOLYSIS: BREAKING DOWN GLUCOSE
  Steps 1-5:
  ATP converted into ADP & high-energy phosphate
released from this process is added to glucose
  These energy-consuming steps prepare glucose
molecule for energy extraction
  energy used in these steps has to be returned to
cell before glycolysis can yield any useful energy
  6 carbon molecule is split into 2, 3-carbon
molecules
Cellular Energy: Glycolysis & Respiration
15
GLYCOLYSIS: BREAKING DOWN GLUCOSE
  Starting at Step 6:
  begins releasing energy
  1 st an electron carrier called NAD + accepts 2
electrons (plus 2 H + ions to balance charge)
  Once NAD + accepts electrons, it becomes NADH;
produces 2 NADH molecules per glucose
  Steps 7 & 10:
  ATP is produced again; 4 ATP are made, 2 from
each 3-carbon molecule. Since cell used 2 ATPs
during early steps of glycolysis, net output is 2
ATPs
Cellular Energy: Glycolysis & Respiration
17
GLYCOLYSIS: BREAKING DOWN GLUCOSE
GLYCOLYSIS: BREAKING DOWN GLUCOSE
GLYCOLYSIS: BREAKING DOWN GLUCOSE
  1 glucose molecule (C 6 H 1 2 O 6 ) 
  2 pyruvic acid molecules (C 3 H 4 O 3 )
  2 NADH ("high energy" electron carrying molecules)
  2 ATP (free, high energy containing molecules)
  4 ATP generated during this process, but 2 are used
during initial stages
11/28/16
Cellular Energy: Glycolysis & Respiration
21
GLYCOLYSIS: BREAKING DOWN GLUCOSE
Glycolysis Animation
http://www.science.smith.edu/
departments/Biology/Bio231/
glycolysis.html
CELLULAR RESPIRATION
  takes place in cell’s mitochondria
11/28/16
Cellular Energy: Glycolysis & Respiration
23
CELLULAR RESPIRATION
  process that involves oxygen & breaks down
food molecules to release energy
  aerobic - needs oxygen!
  b r e a k s d o w n p y r u v i c a c i d f o r m e d d u r i n g
glycolysis, capturing much of remaining energy
from glucose in form of 34 additional ATP
molecules.
11/28/16
Cellular Energy: Glycolysis & Respiration
24
CELLULAR RESPIRATION: KREBS CYCLE
  pyruvic acid produced
during glycolysis goes from
cytoplasm  mitochondria
  Krebs cycle (citric acid cycle)
continuing series of
reactions in cellular
respiration that produces
CO 2 , NADH, & FADH 2
Cellular Energy: Glycolysis & Respiration
25
CELLULAR RESPIRATION: KREBS CYCLE
  Steps of Krebs cycle
  2
  2
  3
  1
  1
C atoms added (from breakdown of pyruvic acid)
C atoms removed (in 2 molecules of CO 2 )
molecules of NAD + converted to NADH
molecule of FAD converted to FADH 2
molecule of GFP converted to GTP
  In each step C atoms in glucose  CO 2
(waste product released from cell)
  Products: 4CO 2 , 6NADH, 2FADH 2 , & 2ATP
11/28/16
Cellular Energy: Glycolysis & Respiration
26
CELLULAR RESPIRATION: ELECTRON
TRANSPORT CHAIN & ATP FORMATION
  high energy electrons from NADH & FADH 2 are passed
to a series of electron transport enzymes in inner
membrane of mitochondria
  these enzymes form an electron transport chain along
which electrons are passed
  with each transfer to a new protein (enzyme) some
energy in NADH is released to form ATP
  at the end of this chain is an enzyme that combines
electrons from electron transport chain, H + from fluid
inside cell, & O 2 to form H 2 O
  O 2 essential in obtaining energy from NADH & FADH 2
11/28/16
Cellular Energy: Glycolysis & Respiration
28
CELLULAR RESPIRATION: ELECTRON
TRANSPORT CHAIN & ATP FORMATION
  produces ATP molecule & H 2 O molecules. ATP
supplies energy for cell. ATP Net Gain: 32 ATP
11/28/16
Cellular Energy: Glycolysis & Respiration
29
ELECTRON TRANSPORT CHAIN
CELLULAR RESPIRATION: ELECTRON
TRANSPORT CHAIN & ATP FORMATION
  as in photosynthesis, movement of H + powers
formation of ATP from ADP
  2 special properties of inner mitochondria that
make process work
  electron transport chains in membrane are
arranged so H ions are pumped in 1 direction
across membrane
  membrane doesn’t allow ions to “leak” back
across (otherwise wouldn’t be enough of a charge
difference to provide energy for ATP synthesis)
11/28/16
Cellular Energy: Glycolysis & Respiration
32
GLYCOLYSIS & CELLULAR RESPIRATION:
ATP FORMATION
11/28/16
Cellular Energy: Glycolysis & Respiration
33
GLYCOLYSIS & CELLULAR RESPIRATION:
TOTAL ATP FORMATION
  Total amount of ATP molecules produced from
each glucose molecule: 36 ATP molecules
  Percentage of total chemical energy available
in glucose this represents: 37%
11/28/16
Cellular Energy: Glycolysis & Respiration
34
OBTAINING ENERGY FROM FOOD
  cell can generate chemical energy in form of
ATP from just about any source (i.e. carbs,
lipids, proteins)
  complex carbohydrates broken down into simple
sugars that are converted into glucose
  most lipids & many proteins can be broken down
into molecules that can enter glycolysis or Krebs
cycle at 1 of several places
11/28/16
Cellular Energy: Glycolysis & Respiration
39
BREATHING & RESPIRATION
  Use term respiration to refer to energy
releasing pathways.
  without oxygen, electron transport cannot
operate, Krebs cycle stops, & synthesis of ATP
in mitochondria stops.
11/28/16
Cellular Energy: Glycolysis & Respiration
40
GLYCOLYSIS & RESPIRATION VIDEO
  Glycolysis Cellular Respiration Overview
  https://adapaproject.org/bbk/tiki-index.php?page=Leaf%3A
+Why+is+glycolysis+called+the+basic+metabolic+pathway
+of+life%3F
  https://www.youtube.com/watch?v=nGRDa_YXXQA
11/28/16
Cellular Energy: Glycolysis & Respiration
41
ENERGY IN BALANCE
  photosynthesis & respiration can be thought
of as opposite processes
PHOTOSYNTHESIS
energy
6CO 2 + 6H 2 0  C 6 H 12 O 6 + 6O 2
11/28/16
Cellular Energy: Glycolysis & Respiration
42
ENERGY IN BALANCE
  photosynthesis & respiration can be thought
of as opposite processes
PHOTOSYNTHESIS
energy
6CO 2 + 6H 2 0  C 6 H 12 O 6 + 6O 2
BREAK DOWN OF GLUCOSE
energy
C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O
11/28/16
Cellular Energy: Glycolysis & Respiration
43
•  takes place in
chloroplast
•  produces
sugar
(glucose)
•  produces O2
•  needs CO2
occur inside
organelles of the
cell
involve many of the
same molecules
involve ATP
use electron
carriers
• takes place in
mitochondria
• needs sugar
(glucose) to
function
• needs O2
• produces CO2
WHY DO PLANTS HAVE BOTH
CHLOROPLAST & MITOCHONDRIA?
1 year from January to December in Oslo, Norway © Eirik Solheim 2011
11/28/16
Cellular Energy: Glycolysis & Respiration
47
WHY DO PLANTS HAVE BOTH
CHLOROPLAST & MITOCHONDRIA?
SUMMER
FALL
WINTER
SPRING
chlorophyll
captures
sunlight &
performs
photosynthesis
chemical
energy
(glucose) is
stored; lose
leaves to
conserve H 2 O
stored energy
keeps plant
alive without
leaves by
breaking down
glucose in
mitochondria
mitochondria
break down
glucose to
release
energy to
produce new
buds to make
leaves
WHY DO PLANTS HAVE BOTH
CHLOROPLAST & MITOCHONDRIA?
  chloroplast & mitochondria transform energy
in the cell & feed off each other’s waste
products
  chloroplast use CO 2 given
off by mitochondria
  mitochondria use O 2 given
off by chloroplasts
11/28/16
Cellular Energy: Glycolysis & Respiration
49
REVIEW
1.  Glycolysis is the process by which glucose is
broken down into pyruvic acid
2.  Breathing is necessary for cellular respiration
in animals because breathing takes in oxygen
which is the final electron carrier in electron
transport chain.
3.  It is considered an aerobic process because for
the end products of the Krebs cycle to be
utilized, oxygen is required (i.e. oxygen is
required for NADH to be converted to NAD + )
11/28/16
Biology: Glycolysis & Respiration
51
REVIEW
1.  What is glycolysis?
2.  List the products of the Krebs cycle. What
happens to each of these products?
3.  Why is breathing necessary for cellular
respiration in animals?
4.  None of the steps of the Krebs cycle involves
oxygen. However, the Krebs cycle is considered
to be an aerobic process. Explain why.
11/28/16
Biology: Glycolysis & Respiration
54
REVIEW
1.  Glycolysis is the process by which glucose is broken down
into pyruvic acid
2.  Products of Krebs cycle & what happens to each product:
CO 2 : released as waste; NADH & FADH 2 : used in electron
transport; GTP: like ATP, provides energy for chemical
reactions
3.  Breathing is necessary for cellular respiration in animals
because breathing takes in oxygen which is the final
electron carrier in electron transport chain.
4.  It is considered an aerobic process because for the end
products of the Krebs cycle to be utilized, oxygen is
required (i.e. oxygen is required for NADH to be converted
to NAD + )
11/28/16
Biology: Glycolysis & Respiration
55