Cell Metabolism (exam 3)

Stop at slide 127

What converts carbon dioxide to carbohydrates

light energy

Photosynthesis is the _ of aerobic catabolism of carbohydrates

reverse

Photosynthesis _ carbohydrates

builds

Cellular Respiration _ carbohydrates

breaks down

Photosynthesis

Reduces CO₂ and H₂O to carbohydrates and O₂

Cellular Respiration

Oxidizes carbohydrates to CO₂ and H₂O

Photosynthesis occurs in _.

chloroplasts

Cellular Respiration occurs in _

mitochondria

What Pathways are involved in both Cellular Respiration and Photosynthesis?

Redox Reactions, Electron transport, Chemiosmosis

Where does photosynthesis occur n Prokaryotes?

in infolded regions of their plasma membrane that function like thylakoids

_ is captured by chloroplasts and is converted into ATP during Photosynthesis

Light energy

What is built from ATP during photosynthesis?

sugars

What are the 2 pathways involved in photosynthesis?

The light reactions and the carbon-fixation reactions

What is consumed in light reactions

water and light energy

What is created from light reactions

O2 and the energy currencies ATP and NADPH

Where do light reactions occur

in the thylakoids

What is a Photon?

An individual “packet” (particle) of light energy

Individual photons of light will contain and amount of energy that corresponds to their _.

Wavelengths

Shorter Wavelengths are _ in energy

Higher

Longer Wavelengths are _ in energy.

lower

Visible light Spectrum

represents photons with the right amount of energy to perform photosynthesis

What do photosynthetic organisms use to absorb light?

pigment molecules

Which photosystem acts first in the process of photosynthesis?

Photosystem 2

What are the 2 components of a photosystem

Antenna complex and reaction center

What does the antenna complex do?

captures the energy of photons and delivers it to the reaction center.

What is the reaction center?

It is where captured energy is used to excite electrons which are then used to reduce electron acceptors.

Light-harvesting complexes

Transmembrane proteins + Pigemnts

Antenna Complex

Light-harvesting complexes + light-harvesting complexes

What are the products of Photosystem 2?

an electron, hydrogen ions (H+) and oxygen gas (O2)

What is the electron from photosystem 2 used for during Electron Transport

It is used to reduce chlorophyll a in Photosystem 1,

Mutation

a change in the sequence of nucleotides of DNA

Steps of Cell Division

step 1: cell receives division signals

step 2: DNA replication (duplication)

step 3: DNA Segregation (separate duplicate DNA)

Step 4: Cytokinesis

Multinucleate Cell

If the DNA is replicated and cytokinesis does not occur, the result would be a single cell with two nuclei

Binary Fission occurs in _

prokaryotes

Cell Division is a _

tightly controlled process

Mutations may be inherited or caused by _

carcinogens

Carcinogens

substances that can cause cancer by increasing the rate of mutations

Examples of carcinogens

tobacco products, radiation, UV light

Normal cells stop at _ during the cellular division process

checkpoints

What checks the conditions of the cell at these checkpoints

proteins

Proteins can _ cell division which can lead to cancer

over-stimulate

Mutations can be repaired by special DNA repair proteins if __

the mutations are caught before the cell divides

When does cancer occur?

when unregulated cell division forms a growing mass of cells with altered functions (due to mutations)

Tumor

Unregulated cell division that forms a mass of cells with altered or no function

Benign Tumor

tumor cells stay localized and do not invade surrounding tissues

Malignant tumor

tumor cells grow into and invade surrounding healthy tissues

Metastasis

Cancerous cells break away from a malignant tumor and start a new cancer at another location in the body

Apoptosis

programmed cell death

Necrosis can cause _

inflammatory reactions

Risk factors

factors that increase a person’s risk of developing a disease, or injury

Stem Cells

are immortal/can divide indefinitely

Mitosis

Produces somatic (AKA body) cells which contain a copy of all the genetic material within an existing parent cell

Meiosis

Produces sex cells (egg and sperm) which contain a copy of half of the genetic material within an existing cell

Gametes

mature sex cells (sperm and egg)

Gonads

organs that produce gametes

Nondisjunction

Failure of homologous chromosomes to separate normally during meiosis

DNA polymerase

the enzyme that replicates DNA

Cytokinesis

The cytoplasm divides to make 2 new cells

Phases of Mitosis

• Prophase

• Prometaphase

• Metaphase

• Anaphase

• Telophase