Chapter 1 : Cell biology and transport

What cells are eukaryotic cells?

animal cell and plant cell

State animal cell structures( 5 structures) and function

1) cell membrane-controls the movement of substances in and out of the cell

2) nucleus-contains DNA and controls the cell' activities

3) mitochondria-releases energy for aerobic respiration

4) ribosome-it is where protein synthesis occurs

5) cytoplasm-jelly-like substance, where chemical reactions occur

State plant cell structures( 8 structures) and function

1) cell membrane-controls the movement of substances in and out of the cell

2) nucleus-contains DNA and controls the cell' activities

3) mitochondria-releases energy from aerobic respiration

4) ribosome-it is where protein synthesis occurs

5) cytoplasm-jelly-like substance, where chemical reactions occur

6) cell wall-made of cellulose, which strengthens the cell

7) chloroplast-contains chlorophyll for photosynthesis

8) permanent vacuole-contains cell sap

What cell is prokaryotic cell?

bacteria cell

State the characteristics of bacteria cell(4 characteristics)

1) single-celled

2) no nucleus- have a single loop of DNA

3) have small rings of DNA called plasmids

4) smaller than eukaryotic cells

State the characteristics of light microscope(5 characteristics)

1) uses light to form images

2) living samples can be viewed

3) relatively cheap

4) low magnification

5) low resolution

State the characteristics of electron microscope(5 characteristics)

1) uses electron a beam to form images

2) samples cannot be living

3) expensive

4) high magnification

5) high resolution

State the equation to calculate the magnification

magnification=image seize divided by actual seize

What is the function of sperm cell?

fertilise an ovum(egg)

What are adaptation of sperm cell?(2 adaptations)

1) tail to swim to the ovum and fertilise it

2) lots of mitochondria to release energy from respiration, enabling the sperm to swim to the ovum

What is the function of red blood cell?

transport oxygen around the body

What are adaptations of red blood cell? (3 adaptations)

1) no nucleus so more room to carry oxygen

2) contains red pigment called haemoglobin that binds oxygen molecules

3) flat bi-concave disc shape to increase surface area-to-volume ratio

What is the function of muscle cell?

contract and relax to allow movement

What are adaptations of muscle cell?(2 adaptations)

1) contains protein fibres, which can contract to make the cells shorter

2) contains lots of mitochondria to release energy from respiration, allowing the muscles to contract

What is function of nerve cell?

carry electrical impulses around the body

What are adaptations of nerve cell?(2 adaptations)

1) branched endings, called dendrites to make connections with other neurones or effectors

2) myelin sheath insulates the axon to increase the transmission speed of electrical impulses

What is function of root hair cell?

absorb mineral ions and water from the soil

What are adaptations of root hair cell?(2 adaptations)

1) long projection speeds up the absorption of water and mineral ions by increasing the surface are of the cell

2) lots of mitochondria to release energy for the active transport of mineral ions and water

What is function of palisade cell?

enable photosynthesis in the leaf

What are adaptations of palisade cell?(2 adaptations)

1) lots of chloroplast containing chlorophyll to absorb light energy for photosynthesis

2) located at the top surface of the leaf where it can absorb the most light energy

What is the definition of diffusion?

net movement of particles from an area of higher concentration to an area of lower concentration

What are four factors that affect to the diffusion?

1) temperature

2) concentration gradient

3) surface area

4) distance

What is the movement of particles of diffusion?

particles move down the concentration gradient from an area of high concentration to an area of low concentration

Is diffusion needed energy?

no-passive process

What is the definition of osmosis?

the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane

What is the movement of particles in osmosis?

water moves from an area of lower solute concentration to an area of higher solute concentration

Is osmosis needed energy?

no-passive process

What is the definition of active transport?

the movement of particles from a more dilute solution to a more concentrated solution using energy from respiration

What is the movement of particles of active transport?

particles move against the concentration gradient-from an area of low concentration to an area of high concentration

Is active transport needed energy?

yes-energy released by respiration

How are villi adapted for exchanging substances?(3 adaptations)

1) long and thin-increase surface area

2) one-cell-thick membrane-short diffusion pathway

3) good blood supply-maintains a steep concentration gradient

How are the lungs adapted for efficient gas exchanged?(4 adaptations)

1) alveoli-large surface area

2) moist membrane-increase rate of diffusion

3) one-cell-thick membranes-short diffusion pathway

4) good blood supply-maintains a steep concentration gradient

How are fish gills adapted for efficient gas exchanged?(3 adaptations)

1) large surface area for gases to diffuse across

2) thin layers of cells-short diffusion pathway

3) good blood supply-maintains a steep concentration gradient

Why is active transport needed in plant roots?

concentration of mineral ions in the soil is lower than inside the root hair cells-the mineral ions must move against the concentration gradient to enter to the root hair cells

What is the purpose of active transport in the small intestine?

sugars can be absorbed when the concentration of sugar in the small intestine is lower than the concentration of sugar in the blood

Give one example of osmosis in a plant?

water moves from the soil into the root hair cell