Photosynthesis: Why Do Temperature and Light Intensity Affect the.

In the event of a sustained change in temperature conditions of plant growth, temperature:Km relationships for key enzyme reactions can adjust towards a temperature optimisation for metabolism and hence growth under those conditions, an out-come referred to above as acclimation and amenable to analysis via an Arrhenius plot to reveal underlying bioenergetics.

Rate of Photosynthesis in Plants?

Count bubbles of oxygen gas given off by elodea to determine the rate of photosynthesis.4.

Rate of photosynthesis is affected by: 1.

Therefore in graph (c) the horizontal axis could be also labelled relative light intensity, a proportional linear relationship with the rate of photosynthesis.

Temperature and Photosynthesis: How Does Temperature.

Hypothesis:Photosynthesis is a process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose....

The rate of diffusion of  into the leaves will also ride as temperature does.

The effect of temperature on photosynthesis 1

One of the more favoured candidates for sensing low temperature is a change in membrane fluidity (i.e. viscosity of the lipid bilayer of cell membranes). This reflects the fact that the structure and fluidity of lipid membranes is dependent on their composition and temperature. Low temperatures decrease the fluidity of lipid membranes as the hydrogen bonding between adjacent fatty acids is increased. The temperature at which membranes undergo a conversion from a fluid state (that exists at warm-moderate temperatures) to a gel-like state (that exists in membranes at low temperatures) is defined as the ‘transition temperature’ (Tm). Tm values as high as 15–20oC have been reported for some species, with increases in the unsaturated fatty acid content of membranes decreasing the Tm. Below the Tm, the function of membrane-bound enzymes and transport of substrates is often reduced owing to the gel-like state of the membrane.

In this experiment we were told that we would be measuring the rate of photosynthesis.

what apparatus can you use to measure the speed of photosynthesis?

Without enough light, a plant cannot photosynthesise very quickly, even if there is plenty of water and carbon dioxide. Increasing the light intensity will boost the speed of photosynthesis.

In practice, any one of these factors could limit the rate of photosynthesis.

Free rate of photosynthesis Essays and Papers - …

Seasonal temperate zone areas with moderate precipitation usually support broad-leafed, deciduous trees, whereas tough-leafed (sclerophyllous) evergreen shrubs, or so-called chaparral-type vegetation, occur in regions with winter rains and a pronounced long water deficit during spring, summer, and fall.

In practice, any one of these factors could limit the rate of photosynthesis.

Increasing Rates of Photosynthesis

Once the change to cold temperatures is perceived and the signal transduced to the nucleus, there follows a substantial reprogramming of the transcriptome, proteome and metabolome of the plant cell (i.e. cold acclimation). The cold acclimation response is best understood in herbaceous annuals such as Arabidopsis thaliana where members of the C-repeat binding factor (CBF or DREB1) family of transcriptional activators, which bind the cis-element known as the C-repeat (CRT)/dehydration-responsive element (DRE), have been shown to control the transcription of a suite of genes that play important roles in the development of freezing tolerance. Subsequent to their discovery in Arabidopsis, many CBF homologues have been found in both monocots and dicots, including perennial species such as aspen, birch and Eucalyptus. The CBF/DREB transcription factors are inducible by stress events but are not normally expressed under non-stress conditions. The plants response to stress therefore requires that there are components within the signal transduction pathway that are constitutively present but only active following the perception of the stress signal. For plant cold responses, a MYC-type bHLH (basic Helix-Loop-Helix) transcription factor, ICE1 (inducer of CBF expression 1), serves as an upstream activator of CBF expression. Transcriptional profiling of the ice1 mutant showed impaired expression of 40% of cold-regulated genes, suggesting ICE1 is one of the main regulators in the cold stress response, but also that it is not the only regulator. ICE1 is constitutively localized to the nucleus and induces CBF expression in a cold-dependent fashion (Figure 14.22). The ability of ICE1 to activate gene transcription in response to cold may be dependent on protein phosphorylation, making ICE1 a likely target of the MAPK cascades activated by the transient increase in [Ca2+]cyt, although the signalling components responsible for this activation are yet to be discovered.